Chemistry Grade 10 (Science New Course)

 

Chemistry           Grade -   10 (Science )

Unit                               Topics
14                    Classification of Elements
15                    Chemical Reaction
16                    Some Gases (CO_2, NH₃)
17                    Metal and Non Metals
18                    Hydrocarbon and its Compounds  19                    Chemicals  used in Daily Life 

                  Unit:-14   Classification of elements       

Periodic table :A table in which elements are classified into various blocks ,periods, and groups on the basis of their similarities and dissimilarities is called periodic table .There are two types lines in the periodic table :
i)Group :The vertical columns of periodic table are called groups .The valence electrons of all elements in the same groups are the  same .The size of atoms increases from top to the bottom in the group of periodic table .
ii)Periods :The horizontal rows of periodic table are called periods .The valence electrons of the elements and the size of atoms increases from left to right in periodic table .
Advantages of periodic table:
i)it help to remember the properties of elements, if its position in the periodic table is known .
ii)It makes the study of chemistry systematic and easy .
iii)It is used as teaching aids in chemistry in school and college .
A.)Mendeleev`s periodic table : The periodic table in which elements are arranged in the table with the increasing order of their atomic weight is called Mendeleev’s periodic table .It was formed by Demitri Mendeleev’s .
Mendeleev’s periodic law: It states that the physical and chemical properties of elements are periodic functions of their atomic weights .
Advantages of Mendeleev’s periodic table :
i)Mendeleev’s periodic table divided the elements into horizontal rows called periods and vertical columns are called groups .
ii)It help to correct the incorrect atomic weights .
iii)Mendeleev’s left proper gaps in the periodic table for undiscovered elements .
iv)There are 8 groups numbered from I  to vii.
v)Physical and chemical properties of the elements are periodic function of their atomic weight .
Drawbacks of Mendeleev’s periodic table :
i)The position of hydrogen could not be explained by Mendeleev’s periodic table i.e. Hydrogen resembles metal as well halogens .
ii)There was not suitable place for lanthanides and actinides    series in the Mendeleev’s periodic table .
iii)Copper ,Gold and silver and alkali metals both were placed in the same groups .
iv) Some elements having higher atomic weight but have been placed before element of lower atomic weights i.e. Ar having At.wt. 39.9 a.m.u. was placed before K having At. Wt. 39.1 a.m.u.
v)The properties like valency ,reactivity ,electro negativity, can not be explained in the terms of periods and groups .

 

Modern periodic table :The periodic table in which elements are arranged in the table with the increasing order of their atomic number is called Modern  periodic table .It is also called long form periodic table .It was formed by Henry Moseley.
Modern periodic law: It states that the physical and chemical properties of elements are periodic functions of their atomic number .
Group: The elements arranged in vertical column of   periodic table is called groups .There are 18 groups. Except zero group and vii the groups from i to vii are divided into sub group A and sub group B .
Period :The elements arranged in horizontal row with increasing order of atomic number are called periods. There are 7 periods and they are numbered as 1^st ,2^nd ,3^rd ,4^th  ,5^th ,6^th and 7^th  periods .

Characteristics of modern periodic table :
i)The elements are arranged on the basis of their increasing atomic  number in the modern periodic table .
ii) There are seven periods i.e. horizontal rows in modern periodic table .

Period	1st	2nd	3rd	4th	5th	6th	7th
N.of elements	2	8	8	18	18	32	26
Form  of Periods	Very short	Short	Short	Long	Long	Very long	Long But incomplet

iii)In the modern periodic table there are 18 groups which are named by following two ways .

According to inter national pure applied chemistry (IUPAC)
1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18
According to modern periodic table
IA	IIA	IIIB	IVB	VB	ViB	VIIB	VIII	VIII	VIII	IB	IIB	IIIB	IVB	VB	VIB	VIIB	0

iv)The elements between group 3 and group 12 are placed between reactive metal and non metal .These elements are called transition metal .These element are also called d-block elements or these elements have variable valency .
v)There are separate place for Lanthanides and Actinides at the bottom of modern periodic table .These elements are also called f-block of elements .

Differences between Mendeleev's and Modern periodic table

Electronic Configuration on basis of sub shell
2n² rule :The rule that gives the maximum number of electrons present in the shell is called 2n²   rule .For example :
i)K- shell = 2n²  
               = 2 x1²  =2 electrons.
ii)L- shell  = 2n²
           =2x 2²    = 8 electrons
iii)  M  -Shell =  2n²
                       = 2x 3²  =18 electrons
Name of shell                                  Number of shell
K  =                                          1
L  =                                          2
M  =                                         3
N=                                           4
O  =                                         5
P  =                                          6
Q   =                                        

Differences between shell and sub shell .

Shell	Sub shell
i)A circular path on which electrons revolute around the nucleus is called shell . ii) It is denoted by K,L,M,N,O,P,Q	i)A part of shell is known as sub shell .ii) It is denoted by s,p,d,f

Difference between orbit and orbital

Orbit	Orbital
i)A circular path on which electrons revolute around the nucleus is called shell . ii)All orbit are circular and disc like .	i)The region around  nucleus in which probability of finding the electrons  maximum is called orbital. ii)Different orbital have shape and half filled or full filled orbital more stable than other .

Valency : The  combine capacity of an elements with another elements is known as velency  .It is represented by  1,2,3,4,5,6 .
Valence shell :The outer shell of an atom of the elements is called valence shell .
Valence electrons : The electrons present in the outer most shell of an atom is called valence electrons .The number of valence electrons determine the valency of an atoms .
Chemical reactivity : The tendency of an elements to take part in chemical reaction is called chemical reactivity .It depends on following factors :
i)Valence electrons   
 ii)Atomic size or radius  
iii)Temperature   
iv)Catalyst
Electronic configuration :The systematic  distribution of electrons according of their shell and sub shell is called electronic configuration.
Electronic configuration formula :

Note :
Metal =Valence electrons :1,2,3 For example :Na, K
Non Metal= Valence electros:5,6,7  for example :Cl,O, Br
Metalloid = valence electrons :4 ,For example:Si, Ge, As, Te
Inert gas: valence electrons: 8 For example:Ne ,Ar, Kr ,xe, Ra
N. of group : Total valence electrons i.e.  IA ,IIA ,IIIA group
N. of  period =: N. of shell
Valency :valence electron 1=1 ,2 =2,3=3,4=4,5=3,6=2,7=1,and 8=0 

For example :A element have 1 electron and B element have  electrons to their valence so A elements can loss easily 1 electrons than that of 2 electrons of B elements therefore A element is more reactive than that of B elements .

For example : A element have 7 electrons and B element have 6 electrons to their valence shell ,so A element easily gain 1 electrons than that of 2 electrons of B elements to complete their valency shell, therefore A element is more reactive than that of B elements .

For example : The atomic size of B element is larger than that of A element ,due larger atomic size of  B element the nuclear attraction to the valence shell is less than that of A element ,so B element can more easily loss 1 electron than that of 1 electron of A element , therefore B element is more reactive than that of A element .

For example : The atomic size of A element is smaller than that of B element ,due smaller atomic size of  A element the nuclear attraction to the valence shell is more than that of B element ,so A  element can more easily gain 1 electron than that of 1 electron of B element , therefore B element is more reactive than that of A element .
Chemical reactivity in period :The chemical reactivity of metal decreases gradually while moving from group 1 to 14 group or left to right side of a period ,similarly chemical reactivity of non- metal increases gradually while moving 15 to 17 group or left to right  in period due to increase of number of valence electron .
Chemical reactivity of metal  ∝  1/Reactivity
Chemical reactivity non metal  ∝ valence electrons
Chemical reactivity in group :The chemical reactivity of metal increases gradually while moving from top to bottom in 1 to 14 group ,similarly the chemical reactivity of non metals decreases gradually while moving from top to bottom in 15 to 17 group due to increase of size of atom .
Chemical reactivity of metal   ∝ atomic size
Chemical reactivity non metal ∝ 1/  size of atom

Classification of elements in modern periodic table :
In modern periodic table the elements are classified following ways :
A.)Metal :The elements which have 1 to 3 electrons to their valence shell are called metals .They can conduct heat and electricity and also can develop electropositive charge by losing electrons .
For example :Elements of IA Gruop to IIIA Group (Exept Boron)i.e.Na,K,Ca and Group IIIB to IIB i.e.Fe,Ag,Au
On the basis of reactivity they are divided in following types :
i)Alkali metal :The elements of IA group in modern periodic table are called alkali metal , because they are dissolve in water to form metal hydroxide or alkali .
These metals are called very reactive metals because they have only one electrons to their valence so loss one electron very quickly to complete their valence shell .They are also called lightest metal .They are soft and have less density.For example  :Na (Sodium), K (potassium ) etc.
ii)Earth alkaline metals :The elements of IIA group in modern periodic table are called earth alkaline metals, because they are found in the form of oxide on the surface of earth and react with water to produce alkali .For example : Mg (magnesium ) Ca (calcium ).
iii)Transition elements : The elements of groups from IB to VIIB and VIII are called transition elements.becausse they have tendency of  reactivity between reactive  elements and Nonmetal.They have variable valency. These elements are also called d-block of elements  .

B.Non metal : The elements which have 4 to 8 electrons to their valence shell are called Non metals .They are bad conductor  heat and electricity and also can develop electronegative charge by gaining electrons . For example :The elements of VA,VIA,VIIA and 0 Group of elements i.e.O,Br,Cl,F,
On the basis of reactivity they are also divided into following types :
i)Chalcogens :The elements of VIA group in modern periodic table are called chalcogens ,because these elements are found combined with copper in nature .For example :O (oxygen), S (Sulphur )  etc .
ii)Halogens: The elements of VIIA group in modern periodic table is called  halogen ,because they react with hydrogen to from acid from which simple salt also can be produced I.e. halogen =salt producer .
This group of elements  are also called very reactive non metal because they have 7 electrons to their valence so they receive 1 electron very to complete their valence .
For example : F (Fluorine) ,Cl (chlorine ) etc.

iii)Noble gas or inert gas :The elements of 0 group in modern periodic table are called Noble gas .because they have already 8 electrons to their valence shell so they neither receive nor donate electrons to complete their valence shell .For example :He (Helium), Ne (Neon) ,Ar (Argon ) etc.
C.Metalloid :The elements which are the poor conductor of heat and electricity are called metalloids or semi conductors  .These elements having both the properties of both metals and non metals .For example :Born (B), Silicon (Si), Arsenic (As) etc.
Block of modern periodic table :On the basis of electronic configuration in sub shell the elements in modern periodic table are divided into 4 blocks :
i)S-block of elements :The elements of modern periodic table having last electron in s-sub shell are called s-block of elements .For example : IA and IIA group of elements .
ii)P-block of elements : The elements of modern periodic table having last electron in P-sub shell are called P-block of elements .For example :IIIA,IVA,VA,VIA,VIIA, and 0  group of elements .
iii)d- block of elements : : The elements of modern periodic table having last electron in d-sub shell are called d-block of elements .For example :IB to VIIB and VIII group of elements .
f-block of elements : : The elements of modern periodic table having last electron in f-sub shell are called f-block of elements .This block is situated at the bottom of modern periodic table .For example :
Lanthanides series :Elements with the atomic n. from 58 to 71 after lanthanum(La) are called Lanthanides series .They are  14 in number also called rarer metal .
Actinides series :Elements with the atomic n. from 90 to 103 after Actinium(Ac) are called Actinides series .They are 14 in number also called artificial radio-active metals.

Atomic size or radius : The distance between the outermost shell and the centre of nucleus of that atom is called atomic size.The Number of positive charge (Proton)present in the nucleus of an atom is called nuclear charge .
i)On moving left to right in a period nuclear charge is increased by one unit and electron is added to the same shell.Therefore electrons are attracted more strongly by nucleus due to which size of atom or atomic size is decreased.
ii)When we move top to bottom in group nuclear charge as well as number of shell are increased due which size of atom or atomic size is increased.
Electro-negativity :The tendency of an atom to attract electrons towards itself when combined in a compound is known as electro-negativity. It increases on moving left to right on moving in a period due to decreases of atomic size .Similarly Electro negetivity of atom decreases from top to bottom in a group due increases of atomic size .
Ionization potential : The amount of energy required to remove a loosely bounded electrons from the shell of an atom .It is measured in electrons volt .It decreases on moving from top to bottom in a group and increase on moving from left to right in a periods .

                                      

                    Unit.:-15    Chemical reaction

Velency:-The combine capacity of element or radical to another element or radial to form compound is called  valency .
Or  the capacity of element to sharing or losing of valence electrons to their valence shell is called valency . It is represented by the numbers i.e. 1,2,3,4,5,6, For example valency of Oxygen is 2 ,hydrogen is 1
Radical :A radical is an atom or group of atoms different element having positive or negative charge and act as single unit during chemical reaction is called radical .They are two types :i)Electropositive radical or Basic radical :The radical which have the capacity of losing electrons and carry positive charge are called electropositive radical .For example Mg⁺⁺ ,(NH₄)
Radical            Valency of elements              Valency of radicals
Ammonium  (NH₄)   = + 5-4                =      +1
 ii)Electronegative radical or acidic radical :The radical which have the capacity of gaining electrons and carry negative charge are called electronegative radical .
For example :O^{-- --}  (SO₄)
Radical            Valency of elements              Valency of radicals
Carbonate (CO₃)  = +4-6                    = -2
Bicarbonate (HCO₃)  = +1+4 -6                   = -1
Sulphate (SO₄)     = +6-8                    =2
Bisulphate (HSO₄)  =+1+6 -8                       =  -1
Nitrate (NO₃)  = +5-6                                     = -1
Hydroxide (OH) = -2+1                                   = -1

Valency Chart

S.N	Name of Elements	Symbol		Valency
		Electro Positive	Electro Negative
1	Hydrogen  or hydride	H		1
2	Potassium	K		1
3	Sodium	Na		1
4	Silver	Ag		1
5	Gold-I(Aurous)	Au		1
6	Copper –I (Coprous)	Cu		1
7	Mercury –I(Mercurous)	Hg		1
8	Ammonium	(NH4)		1
9	Bicarbonate		(HCO3)	1
10	Bisulphate		(HSO4)	1
11	Hydroxide		(OH)	1
12	Nitrate		(NO3)	1
13	Nitrite		(NO2)	1
14	Chlorate		(ClO3)	1
15	Chlorite		(ClO2)	1
16	Chlorine or chloride		Cl	1
17	Bromine or bromide		Br	1
18	Fluorine  or fluoride		F	1
19	Iodine or iodide		I	1
20	Cyanide		CN	1
21	Bisulphite		(HSO3)	1
22	Barium	Ba		2
23	Calcium	Ca		2
24	Magnesium	Mg		2
25	Nickel	Ni		2
26	Zinc	Zn		2
27	Coppper –II(Cupric)	Cu		2
28	Iron –II(Ferrous)	Fe		2
29	Mercury –II(Mercuric)	Hg		2
30	Lead –II (Plumbous)	Pb		2
31	Tin-II(Stannous)	Sn		2
32	Magnanese	Mn		2
33	Iron –II(Ferrous)	Fe		2
34	Oxygen or oxide		O	2
35	Sulpher or Sulphide		S	2
36	Peroxide		O2	2
37	Carbonate		(CO3)	2
38	Sulphate		(SO4)	2
39	Sulphite		(SO3)	2
40	Chromate		(CrO3)	2
41	Dichromate		(Cr2O7)	2
42	Silicate		(SiO3)	2
43	Stanate		(SnO3)	2
44	Aluminium	Al		3
45	Nitrogen or Nitride		N	3
46	Phosphrous  or phosphide		P	3
47	Chromium	Cr		3
48	Iron-III (Ferric)	Fe		3
49	Gold –III (Auric)	Au		3
50	Phosphate		(PO4)	3
51	Lead –IV (Plumbic)	Pb		4
52	Tin-IV(Stanic)	Sn		4
53	Sulpher or sulphide	S		4
54	Silicon	Si		4
55	Carbon or carbide	C		4
56	Nitrogen or nitride	N		5
57	Phosphrous	P		5
58	Sulpher	S		6

Molecular formula :The symbolic representation of molecules of substance which show actual number of atoms present in the molecules is called molecular formula or chemical formula .For example :i) Magnesium chloride =MgCl₂, Sodium sulphate =Na₂(SO₄ ) etc.
Ways of writing molecular formula : This method is called criss –cross method.
i)Write the symbols side by side but electropositive is written first and then electronegative .
ii)Write the valency of each atom at top of its symbol .
iii)Divide the valency numbers by highest common factor then inter change the valency of symbol .
iv)Write the  inter changed valency number to the lower of the symbol .
For example:

Molecular formula of some compounds :
Name of compounds           Molecular formula
Water =                      H₂O
Carbondixide             =            CO₂
Carbonmonoxide =    CO
Ammonia          =        NH₃
Castic soda                 =    Na(OH)
Castic Potash                         = K(OH)
Methene                     = CH₄
Calcium carbonate  or limestone     =Ca(CO₃)
Lime water                 = Ca(OH)₂
Lime                            ₌ CaO
Hydrochloric acid      =HCl
Sulphuric acid                        H₂(SO₄)
Nitric acid                   =H(NO₃)
Carbonic acid                         =H₂(CO₃)
Acetic acid                  =CH₃COOH
Carbon sulphide        =CS₂
Nitric oxide                =NO
Hydrogen peroxide   =H₂O₂
Iron oxide (rust)                     =Fe₂O₃
Manganese dioxide   =MnO₂
Silica(Silicon oxide ) =SiO₂
Urea                            =NH₂-CO-NH₂
Diatomic elements    =H_2,O_2,N_2,Cl_2,Br_2,I_2,F_2,

Chemical reaction :-The exchange ,combustion or decomposition that occurs in the molecules of substances during a chemical change is called chemical reaction .
Chemical equation : The symbolic representation of the chemical reaction by writing the symbol and formula is called chemical equation .It is divided into two parts :
i)Reactant :The substance which takes part in chemical are called reactants .They are always  written in the left side of the chemical equation .
ii)Product :The substance obtained from a chemical reaction are called product .They are always written in the right side of the chemical equation .
i)Hydrogen +Oxygen                  Water
2H₂    +O_{2    →}         2 H₂O
ii)Sodium +Oxygen                  Sodium oxide
Na +O_{2         →}      Na₂O
Word equation :The chemical equation in which the names of substance and products are expressed in the form of word is called word equation . For example :
 i)  Hydrogen + Oxygen    _→         water
ii) Magnessium + Oxygen   _→     Magnesium oxide
iii)Calcium carbonate          _→    Calcium oxide +Carbon dioxide

Types of chemical reactions :There are 4 types chemical reaction:
1)Combination reaction :The chemical reaction in which two or more elements or compounds combine to form a single compound is called combination reaction .For example :
1)Sodium + Oxygen  _→      Sodium oxide
4Na     `+ O_{2        →}     2Na₂O
2)Magnesium + Oxygen       _→    Magnesium oxide
2Mg     +          O_{2       →}   2MgO
3)Hydrogen + Chlorine      _→  Hydrogen chloride
H₂   +  Cl_{2              →}     2 HCl
4)Zinc +Chloride  _→   Zinc Chloride
Zn  + Cl_2   →       ZnCl₂
5)Nitrogen + Hydrogen       _→    Ammonia
N₂      +     2H_{3    →}       2NH₃
6)Iron + Oxygen    _→    Iron oxide
Fe   +  O_{2        →}               Fe₂O₃
7)Magnesium +Nitrogen     _→     Magnesium Nitride
3Mg +  N_2   →          Mg₃N₂
8)Carbon dioxide +Water   _→     Carbonic acid
  CO₂        +H₂O     _→      H₂CO₃
9)Aluminum + Oxygen         _→    Aluminum oxide
4Al  +3O_{2                            →}          2 Al₂O₃
10)Aluminum + Chlorine    _→      Aluminum Chloride
2Al    + 3Cl_{2              →}             2AlCl₃
11)Ammonia +Hydrochloric acid    _→      Ammonium chloride
NH₃       + HCl        _→      (NH₄)Cl
12)Nitrogen +  Oxygen   _→     Nitric oxide
N₂     + O_{2              →}          2NO
13)Calcium oxide + Water    _→                Calcium hydroxide
CaO     +  H₂O           _→             Ca(OH)₂
14)Sodium oxide        +Water       _→                  Sodium hydroxide
Na₂O   +H₂O       _→                       2Na(OH)
15)Magnesium oxide +Water                _→           Magnesium hydroxide
16)Ammonium oxide +Water  _→           Ammonium hydroxide
 (NH₄)₂O    + H₂O       _→                2(NH₄)(OH)

2.)Decomposition  reaction :-The chemical reaction in which a compound split or decompose into two or more elements or compound is called decomposition reaction .For example:
1)Water        _→     Hydrogen   + Oxygen
2H₂O             _→     2H₂     + O₂ 
2)Potassium chlorate    _→   Potassium chloride + Oxygen
2K(ClO₃)    _→     2KCl     + 3O₂
3)Calcium carbonate     _→  Calcium oxide +Carbon dioxide
Ca(CO₃)     _→    CaO    + CO₂
4)Magnesium oxide       _→    Magnesium +Oxygen
2Mg O       _→    Mg + O₂
5)Hydrogen peroxide   _→    Water + Oxygen
2H₂O_{2    →}                     2H₂O +O₂
6)Calcium bicarbonate    _→  Calcium carbonate +Carbon dioxide +Water
Ca(HCO₃)_{2   →}   Ca(CO₃) +CO₂    +H₂O
7)Magnesium bicarbonate  _→ Magnesium carbonate +Carbon dioxide +Water
Mg(HCO₃)_{2         →}   Mg(CO₃) +CO₂  +H₂O
8)Silver Bromide     _→   Silver  + Bromine
2Ag Br       _→       2Ag  +Br₂
 9)Potassium Permanganate  _→ Potassium manganate +Manganese dioxide +Oxygen
2KMnO_{4     →}   K₂MnO₄ +MnO₂  +O₂
10)Ammonium carbonate _→  Ammonia +Carbon dioxide +Water
(NH₄)₂(CO₃)  _→  2NH₃    +CO₂    +H₂O

3.Displacement reaction :The chemical reaction in which an element or radical of a compound is displaced by another element or radical of compound is called displacement reaction .For example :
1)Zinc +Sulphuric acid    _→     Zinc sulphate +Hydrogen
Zn +  H₂(SO₄)  _→   Zn(SO₄ )  +   H₂
2)Zinc  + Hydrochloric acid   _→  Zinc chloride + Hydrogen
 Zn       +   2HCl   _→    ZnCl₂   +  H₂
3)Potassium + Nitric acid   _→   Potassium Nitrate +  Hydrogen
 2 K  + 2H(NO₃) _→   2K(NO₃)    +  H₂
3)Iron + Copper Sulphate  _→   Iron Sulphate +Copper
2 Fe +3 Cu(SO₄)   _→   Fe₂(SO₄)₃   + 3Cu
4)Aluminum  + Hydrochloric acid   _→   Aluminum chloride +Hydrogen
2 Al      +6 HCl  _→    2AlCl₃  + 3 H₂
5)Magnesium + Copper Sulphate   _→  Magnesium Sulphate + Copper
 Mg + CuSO_{4    →}      Mg(SO₄)  + Cu
6)Sodium + Water  _→    Sodium hydroxide + Hydrogen
2 Na +2H₂O    _→   2Na(OH) +H₂
 7)Magnesium+ Water     _→   Magnesium hydroxide +Hydrogen
 Mg + H₂O      _→   Mg(OH)₂          +H₂
8)Zinc +Silver Nitrate  _→  Zinc Nitrate +Silver
 Zn + 2Ag(NO₃)        _→   Zn(NO₃)₂  +2Ag
9)Calcium +Water       _→  Calcium hydroxide +Hydrogen
 Ca +2H₂O      _→      Ca(OH)₂ +H₂
10)Aluminum +Sulphuric acid       _→  Aluminum Sulphate+ Hydrogen
2Al+3 H₂(SO₄)      _→    Al₂(SO₄)₃ +6H₂
11)Copper +Silver Nitrate    _→   Copper Nitrate +Silver
 Cu +  2Ag(NO₃)           _→    Cu(NO₃)₂ +2 Ag
12)Ammonia +Chlorine    _→  Ammonium Chloride +Nitrogen
8NH₃ +3Cl_{2            →}             6 ( NH₄)Cl     +N₂    
13)Calcium Chloride +Silver Nitrate      _→  Calcium Nitrate +Silver Chloride
CaCl₂ + 2Ag(NO₃)   _→     Ca(NO₃)₂+2AgCl
14)Calcium Carbonate +Hydrochloric acid      _→  Calcium Chloride +Carbon dioxide +water
Ca(CO₃) +2HCl     _→  CaCl₂ +CO₂ +H₂O
15)Sodium Chloride +Silver Nitrate   _→   Sodium Nitrate+ Silver Chloride
 NaCl +Ag(NO₃)    _→    Na(NO₃)+ AgCl
16)Calcium Carbonate +Sulphuric acid     _→  Calcium Sulphate +Carbon dioxide +Water
Ca(CO₃)+H₂(SO₄)       _→    Ca(SO₄)+CO₂ +H₂O
 
17)Magnesium Sulphate +Sodium Carbonate     _→  Magnesium Carbonate
 +Sodium Sulphate
Mg(SO₄)+Na₂(CO₃)  _→    Mg(CO₃)+Na₂(SO₄)

4)Acid –Base reaction :The Chemical reaction in which an acid react with a base to form salt and water is called acid- base reaction .In acid base reaction both acid and base loss their properties during chemical reaction and form neutral substance salt and water ,so it is also called Neutralization reaction .
Some acids :
i)Hydrochloric acid=HCl
ii)Sulphuric acid =H₂(SO₄)
iii)Nitric acid =H(NO₃)
iv)Carbonic acid =H₂(CO₃)
Some bases :
i)Metal oxide ePdf = Mgo,Na₂O,K₂O,CaO etc.
ii)Metal hydroxide ePdf = Na(OH),K(OH),Ca(OH)₂ etc.
1)Sodium Hydroxide +Hydrochloric acid    _→   Sodium Chloride + Water
2Na(OH)+2HCl        _→    2NaCl +H₂O
2)Sodium Oxide +Hydrochloric acid    _→   Sodium Chloride +Water
Na₂O   +2HCl     _→    2NaCl +H₂O
3)Calcium Oxide +Sulphuric acid  _→   Calcium Sulphate +Water
CaO +H₂(SO₄)   _→       Ca(SO₄)+H₂O
4)Magnesium Oxide +Hydrochloric acid   _→    Magnesium Chloride +Water
MgO+2HCl         _→     MgCl₂ +H₂O
5)Potassium Hydroxide + Hydrochloric acid   _→  Potassium Chloride +Water
2K(OH)+2 HCl   _→      2KCl +H₂O
6)Sodium Hydroxide +Sulphuric acid     _→    Sodium Sulphate +Water
2Na(OH) +H₂(SO₄)  _→     Na₂(SO₄)+2H₂O
7)Ammonium Hydroxide +Sulphuric acid      _→  Ammonium Sulphate + Water
2(NH₄)(OH) +H₂(SO₄)      _→   (NH₄)₂(SO₄)+H₂O
8)Magnesium Hydroxide + Nitric acid      _→   Magnesium Nitrate + Water
Mg(OH)₂ +2H(NO₃)       _→    Mg(NO₃)₂   +H₂O
Types of reaction according to heat :There are two types of reaction according to heat :
1.)Exothermic reaction : The reaction in which heat is released to the surrounding  is called exothermic reaction. For example :
i )C + O _{2        →}       CO₂  +Heat
ii) C₆H₁₂O₆ +6O_{2     →}   6CO₂ + 6H₂O Energy +Heat
2.)Endothermic reaction :The reaction in which heat is absorbed from the surrounding is called endothermic reaction .For example :
i)Ca(CO₃)  + Heat        _→   CaO +CO₂
ii)2K(ClO₃)   _→         2KCl + 3O₂

Some rules of what happens :
Reactants                                                       Product
i)Single 2 elements   =    Combination of element .i.e.
Na + Cl_{2          →}            NaCl
Mg + O_{2                  →}        MgO
ii)Metal  +Water =      Metal Hydroxide i.e.
Na+ H₂O       _→           Na(OH)
Ca  +H₂O      _→        Ca(OH)₂
iii)Metal +Water  = Metal Hydroxide +Hydrogen i.e.
 Mg + 2H₂O       _→     Mg(OH)₂ +H₂
Na+2 H₂O    _→         Na(OH)₂  +H₂
iv)Acid+ Base  = Salt + Water
 HCl +Na(OH)     _→     NaCl +H₂O
H₂(SO₄) +Na₂ O     _→   Na₂(SO₄) +H₂O
v)Carbonate + acid =  Carbon dioxide + Water  i.e.
 Ca(CO₃)+2HCl     = CaCl₂  + CO₂  +H₂O

Balanced chemical equation : The chemical equation written by balancing the N. of atoms of element on both sides of reactants and products is called balanced chemical equation .For example :
2H₂ + O_{2      →}           2H₂O
Advantages  or information can be obtained from of balanced chemical reaction : Following information can be obtained from balanced chemical equation :
i)The types of chemical equation
ii)Names of reactants and produced
iii)Molecular formula  or symbols of reactants and products
iv)N. of atoms and molecules of reactants and products .
Limitation of a balanced chemical equation :The information which can not show a balanced chemical equation are called limitation of balanced chemical equation .They are as following :
i)Rate of chemical equation .
ii)Concentration of reactants .
iii)Duration of chemical reaction .
iv)Conditions necessary for chemical reaction .

The rate of chemical reacton :The time taken from the start of a chemical reaction to its ends is called the rate of reaction .Different chemicals react to each other a different rates .For example :Chemical reaction of rusting of iron occurs very slowly,but reaction between sodium and woter occurs very fast to releases hydrogen .

Factors affecting chemical reaction or chemical change :  Some of the  Factors  which affect  the rate of the chemical reaction are called factors  affecting chemical reactions. 
1)Heat :When reactants are heated more kinetic energy provides to the reactants molecules ,that increase the rate of reaction by colliding with one another molecules .i.e.
C+Calcium Carbonate        _→Heat      Calcium oxide +Carbon dioxide                    
   Ca(CO₃)         _→                         CaO + CO₂
2)Light :Light makes the reactants molecules more reactive and help to
i.Silver Bromide    _→            ^Light     Silver +Bromide
2AgBr     _→     ^Light    2Ag + Br₂
ii.Carbondioxide +water _{→   Light /Chlorophyll}     Glucose + Oxygen
 CO₂   + H₂O    _{→  Light /Chlorophyll}      C₆H₁₂O₆  +O₂
iii.Siver Nitrate _{→  Light}  Nitrogendioxide  +Oxygen  +Silver
2 Ag(NO₃) _{→  Light}              2 NO₂      + O₂     +2Ag 
3)Electricity :The electrical energy help the ions to move to wards  opposite. charged electrodes that brings out a chemical change and increase the rate of reaction .
Water      _→      Hydrogen +Oxygen
2H₂O    _→     ^Electrolysis    2H₂ +   O₂
4)Direct Contact :Some  active substance react on coming in direct contact with other .i.e.
Sodium + Chlorine   _→ ^{Direct contact}  Sodium Chloride
2Na + Cl_2  →    ^{Direct contact}     2 NaCl
5)Pressure :Some chemical reaction takes place by the application of pressure .i.e.
Nitrogen + Hydrogen _→  ^{200 atm-900 atm}  Ammonia
N₂  +3H_2  →  ^{200 atm-900 atm}     2 NH₃
6.)Surface area :The rate of chemical reaction is directly proportional to the surface area of the reacting molecules ,because there is more chances to contact and collision between reacting particles .For example :During preparation of hydrogen gas if the granulated zinc has more area the chemical reaction proceeds in faster rate .
7.)Solution :The chemical reaction between some compounds only occurs when they are in the state of solution .For example :Silver nitrate and Sodium chloride only react when they are mixed in the solution state
Ag(NO₃) (aq.) + NaCl (aq.)       _→   Na(NO₃) +AgCl
8.)Concentration : The rate of chemical reaction increase with the increase in the concentration of the reactants because concentration of reactants increase reactants molecules .
9)Catalyst :A chemical substance which changes the speed of rate of chemical reaction with out changing itself is called the catalyst . There are 2 types of catalyst :
i)Positive catalyst :A catalyst which increase the rate of chemical reaction is called positive catalyst .i.e. Manganese dioxide(MnO₂),Vanadium Pentoxide(V₂O₅),Iron(Fe) acts as positive catalyst in a decomposition reaction of potassium chlorate .
Potassium Chlorate     _→   MnO₂   Potassium Chloride + Oxygen 
2K(ClO₃)    _→  MnO₂        2KCl +3O₂
ii)Negative Catalyst :A catalyst which decrease the rate of chemical reaction is called negative catalyst .i.e. Glycerin,Phosphoric acid (H₃PO₄) acts as negative catalyst in decomposition of hydrogen peroxide .
2H₂O_2  →   Glycerin   2H₂O  + O₂

Gram atomic weight : The atomic weight of an element expressed in gram is known as gram atomic weight of that element .For example :The gram atomic weight of oxygen is 16 gm ,because the atomic weight of oxygen is 16 .
1.)Find the atomic weight of Na, K ,and Ca atoms .
            Na =11+12
                 =23 gm
           K = 19+20
               =  39 gm
          Ca =20+20
               = 40 gm
Gram molecular weight :The molecular weight of the substance is expressed in gm is known as gram molecular weight of that substance .For example :The gram molecular weight of water is (H₂O) is 18 gm because molecular wt of water is 18 .
1.)Find the molecular weight of given compounds .
i)H₂O
= 1x2+16
18 gm
ii)CaO
= 40+16
=56 gm
iii)Ca(CO₃)
= 40+12+16x3
=40+12+48
=100gm
1mol: The gm atomic wt. or gram molecular of any substance is known as 1 mol of that substance .
1 mol of any substance =Gm atomic weight or Gm molecular wt of that substance .
i)Calculate the mass of 8 mol of water .
Gram molecular weight of water =H₂O
                                                            =1x2+16
                                                            =18 gm.
Mass of 1 mol of water =Gram molecular wt. of water
                                            = 18gm .
Therefore ,mass of 8 mol of water =18x8
                                                                 =144gm.
ii)Convert 5 gm of Ca  into mol .
Gram at. wt. of Ca =1 mol of Ca
40 gm of Ca = 1mol of Ca
1gm of Ca  =1/40
؞5 gm of Ca =1/40   x 5
  Therefore 5 gm of Ca = =0.25 mol of Ca 

Unit :-16     Gases (Carbon dioxide (CO₂), Ammonia (NH₃)

A) Carbondioxide =CO₂
1.Indtroduction :The molecular formula of carbon dioxide is CO_2,molecular weight is 44 a.m.u.  Air contains about 0.03% of carbon dioxide by volume .Its molecular structure is

2.Methods of general preparation of CO₂ :
1.)When carbon is burn in air with plenty of oxygen and carbon dioxide is obtained .
C +O₂     →   CO₂
                        Carbon dioxide
ii.)When calcium carbonate is heated strongly and carbon dioxide is obtained .
Ca(CO₃)     →   CaO     +  CO₂
Lime stone       Lime
iii)When fuel like methane, ethane ,is burn in air carbon dioxide is obtained.
CH₄    +    2O₂   →     CO₂   +2 H₂O
Methane
3.)Method of lab. preparation CO₂  gas :
i.)Apparatus required :Wolf bottle ,Thistle funnel ,delivery tube, gas jar, beehive self, heating apparatus.
ii)Chemicals required:  Lime stone (marble), hydrochloric acid 
iii)Principle:- CO₂  gas  can be  prepared by treating pieces of calcium carbonate with  dil. Hydrochloric acid .

Reaction :
Ca(CO₃)      +   dil. HCl   →   CaCl₂   +  CO₂  + H₂O
Lime stone
iv)Precaution: a)The apparatus should be made air tight .
b)The end of thistle funnel should be dipped into the acid in wolf bottle.
v)Test of CO₂ :a) When a burning match stick is placed near the mouth of gas jar containing CO₂ .If match stick extinguish the gas is CO2 gas ,because CO₂ gas is non supporter of combustion .
4.)Properties
1.)Physical properties :
i)It is colourless ,odourless and testless gas .
ii)It turns wet blue litmus paper into red .
iii)It is heavier than that of air .Therefore CO₂ gas can be collected down word displacement method of water  or it is collected by upward displacement of air .
iv)It dissolve in water so, it is not collected in water .
v)It is non supporter of combustion .
Chemical properties :
i)When carbon dioxide is treated with water carbonic acid is obtained .Therefore when blue litmus paper is introduced inside gas gar containing CO₂ it change in to red colour due to formation of carbonic acid.
CO₂  +    H₂O        →      H₂(CO₃)
ii)When carbon dioxide is passed into lime water for long time in the beginning milky solution of insoluble calcium carbonate is obtained
If when carbon dioxide is passed continuously in the solution for long time the milky ness  disappear slowly due to the formation of water soluble calcium bicarbonate .
a)Ca(OH)₂    + CO₂        →     Ca(CO₃) +H₂O
Lime water                                 Milky sol_.
b)Ca(CO₃)  +H₂O        →    Ca(HCO₃)₂
iii)When burning magnesium ribbon is introduced into  gas jar filled with CO₂ ,white colour of MgO is produced along with the formation of black spots of  carbon .
2Mg  + CO₂     →       2Mg O      + C                                   
                                                                    Black
iv)When carbon dioxide react with water in presence of chlorophyll, and sun light ,Glucose and oxygen is obtained .
6CO₂    +   6H₂O  →    C₆H₁₂O₆    + 6O₂
                                                               Glucose
v.)Take a test tube containing carbondioxide gas and pour 2-3 drops of KOH into it .Then close the mouth of test tube and put into water in an inverted position.In this reaction KOH absords maximum amount of water and form K₂CO₃    and water .
CO₂  +  KOH   →    K₂CO₃    +H₂O

5.)Method of industrial preparation of CO₂  gas :
In industries carbon dioxide gas is prepared in large scale by heating lime stone at very high temp.  in the furnace .In this process lime is also produced .
Ca(CO₃)         ^Heat  →     CaO  +CO₂
Lime stone                    Lime
6.)Uses :
i)It is used by all green plant during photosynthesis .
ii)It is used as fire extinguisher .
iii)It is used for making dry ice to preserve meat, fruit etc. (A solid form of carbon dioxide which is obtained by cooling it about -78⁰C is called dry ice .
iv)It is used for making  urea fertilizer .
v)The mixture of oxygen((85% to 90%) and carbondixide (10% to 15%) is called carbogen which is used to provide artificial respiration because it increase the rate of respration .

Fire extinguisher :

Afire extinguisher is a metallic cylinder divided in to two section .The outer section is a metallic covering contains sodium bicarbonate =Na(HCO₃) and inner section is made up a glass vessel filled with conc. Sulphuric acid =H₂(SO₄)_.When  glass vessel is broken by pressing knob at the top of cylinder sulphuric acid gets mixed with sodium bicarbonate to form carbon dioxide .

 2Na(HCO₃) + H₂(SO₄)          →    Na₂(SO₄) +2H₂O+ 2CO₂

B.)Ammonia (NH₃)
1.)           Introduction :
La Voiser prepared first time ammonia gas .Its molecular formula is NH₃ ,molecular weight is 17 a.m.u. and its molecular structure is

Methods of general preparation of NH₃ gas :
i)When magnesium Nitrate is treated with water and ammonia gas is formed .
Mg₃N₂ +  6H₂O     →         3Mg(OH)₂ +2NH₃
3.)Methods of lab preparation of ammonia gas :
i) i.)Apparatus required :Round bottom flask ,delivery tube, gas jar, , heating apparatus, lime tower
ii)Chemicals required:  Ammonium chloride ,Calciumhydroxide.
iii)Principle:- NH₃  gas  can be  prepared by treating mixture of Ammonium Chloride and of calcium hydroxide .
iv)Reaction :
2(NH₄)Cl  + Ca(OH)₂        →        CaCl₂  + H₂O  + 2NH₃
                                                                                            Ammonia

                                                   Fig.  Lab preparation of NH₃  gas .

v)Precaution :
i)The apparatus  should made air tight.
ii)The should be collected in gas jar by the downward displacement .
vi)Test of NH₃ gas :When a wet a red litmus paper is introduced in to gas jar containing ammonia gas . It change into blue colour due to formation of Ammonium hydroxide alkali .
4.)Method of industrial preparation of NH₃ gas : In industries  ammonia is prepared by Hyber’s process .In this process  ammonia gas is prepared by the direct combination of Nitrogen and Hydrogen gas under high pressure and high temperature in presence of  Fe catalyst .
N₂   +  3H₂   →        ^200atm/500C        2NH₃
                                                             Ammonia

5.)Properties :
Physical properties :
i)It is colourless ,testless , but strong pungent odour .
ii)It is highly soluble in water .
iii)It is lighter than that of air .
iv)It turns wet red  litmus paper  into blue colour due to formation ammonium hydroxide alkali.
Chemical properties .
i)When ammonia react with water an alkali ammonium hydroxide is formed .
NH₃   +  H₂O →                (NH₄)(OH)
                                             Alkali
ii) When ammonia react with acid ,salt are formed .
NH₃   +  HCl  →                 (NH₄)Cl
NH₃   +  H(NO₃)       →     NH₄(NO₃)
iii)When ammonia is treated with carbon dioxide at high temperature at 1500 ⁰C under certain pressure urea is formed .
2NH₃  +  CO₂        →                     NH₂ – CO – NH₂   + H₂O
                                                            Urea
iv.)When ammonia gas is burn with oxygen water and Nitrogen gas is obtained
4NH₃   +  3O₂     → 2  N₂   + 6H₂ O
v)When ammonia gas is treated with Oxygen gas at high temp.in presence of Pt. at catalyst Nitric oxide and water is obtained .
4NH₃  + 5O₂     →high temp/pt.       6H₂O  + 2NO
Vi )When ammonia is sent in melt Sodium metal Sodamide and Hydrogen gas is obtained .
2NH₃  +  Na      →    2 NaNH₂ + H₂
 
6.)Uses :
i)It is used for making chemical fertilizer .i.e. urea, ammonium sulphate .
ii)It is used for making  plastic, washing soda  etc.
iii)It is used for making medicine .
iv)It is used for develop blue print .
v)It is used in refrigerator in cooling agent .
vi)It is used as cleansing agent for oil,greeze etc. 
1.)Lime tower is used in lab preparation of ammonia gas ,why?
Ans. Lime tower help to form dry ammonia gas ,because when ammonia gas comes out from lime tower ,it absorb water of ammonia gas due to water soluble properties of ammonia .
2.)The mouth hard glass test tube is slightly slanted during the preparation of ammonia gas ,why ?
Ans. When mixture of (NH₄)Cl and Ca(OH)₂  is heated steam is formed and reach upper end of steam but when it liquefied come back at the bottom of test .It may cause cracking of test tube ,so hard glass test tube is slightly slanted to prevent of cracking .

Green house effect: The increase of temperature of earth by trapping the solar heat in earth by green house gases( i.e.CO_2,N₂O,CH₄,CFC_s and water vapour) is called green house effect

Effects of green house:
i)It causes the skin and eye cancer .
ii)It help spreading diseases like malaria, filarial ,etc.
iii)It help to increase temperature and which effect water cycle and reduce production of crops .
iv)Global warming is caused by green house effect so snow of polar will melt and it will increase sea by which Island may disappear  in ocean .
v)It causes the increase surface temperature of earth and living being can survive on earth surface.
Methods of controlling green house effects:
i)by reducing use of fossil fuels .
ii)By increasing afforestation .
iii)By banning use of CFC_s.
Artificial green house: The houses made up of plastic ,or glass for the cultivation of plants and crops inside it are called artificial green house .
The temperature inside the green house is always more than that of outside it ,because glass or plastic allow inter sun radiation but when strike on the ground it change into wave have less energy or longer wave length that can not  go out from the house and get reflected inside house as result due to accumulation of more sun radiation the temperature of inside the increases.

Uses or advantages : i)It is used to grow different crops in off seasons i.e. summer plant can be grow in winter season and the plant of terai can be grow in mountain region.
Earth is considered as natural green house :
Earth can be described as a natural greenhouse, because The natural greenhouse effect is a process in which certain gases in Earth's atmosphere, such as carbon dioxide and water vapour, trap heat from the Sun and warm this planet. This process is essential for maintaining a habitable temperature range on Earth, allowing life to thrive.

i)CO₂+ H₂O                _→          H₂CO₃(carbonic acid)
ii)SO_{2      →}^oxidation           SO₃ + H₂O       _→       H₂SO4 (Sulphuric acid)
iii) 2NO₂+2H₂O +O_{2            →}          4HNO₃(Nitric acid)
Effects of acid rain:
i)Acid rain damages the building and sculptural materials i.e.lime stone and marbles .
ii)It causes of the loss of nutrients from plant foliage and it damages the leaves and trees.
iii)It remove basic nutrients i.e. calcium from soil.
iv)It increase the acidity of soil  that reduce the fertility of soil.
v)it also damages the lot of crops ,plants etc.
 
Control measures of acid rain :
1.We should reduce the emission of oxides of nitrogen and sulphur .
2.Alternative source of energy like solar energy,wind energy,should be used.
3.The use of hydroelectricity and nuclear fuel should be used instead of fossil fuels.
4.The use of renewable source of energy should be increased.
5.Plantation program should be conducted .

   

             Unit: 17.      Metal and Non Metals

Minerals :   Naturally occurring, inorganic substances that have a specific chemical composition and a crystalline structure is called Mineral . They are the building blocks of rocks and are found in the Earth's crust. Minerals  are the composed of various elements, such as oxygen, silicon, aluminium, iron, calcium, and many others Elements.
Uses of minerals:
1. Construction: Minerals like limestone, granite, and sand are used in construction materials.
2. Metals and Alloys: Many minerals are sources of valuable metals like iron, copper, aluminium, and gold.
3. Energy Production: Minerals play a major role in energy production. For example: Coal, oil, and natural gas are fossil fuels that are extracted from the from earth as minerals.
4. Manufacturing: Various minerals are used in manufacturing industries. For example, quartz and feldspar are used in the production of glass and ceramics.
5. Agriculture: Minerals are essential for agriculture. Fertilizers contain minerals like nitrogen, phosphorus, and potassium, which are necessary for plant growth and crop production.
6. Health and Medicine: Minerals have important roles in human health. For example: Calcium and phosphorus are crucial for bone health. Iron is necessary for the production of haemoglobin in red blood cells.
7. Electronics and Technology: Minerals such as silicon, aluminium, copper, and gold are used in the production of electronic devices, computer chips, wiring, and circuit boards.
8. Gemstones and Jewellery: Certain minerals, when cut and polished, are used as gemstones. For examples  diamonds, rubies, emeralds, sapphires, and amethysts  are used in jewelry and decorative items.
Ores:
Naturally occurring minerals or rocks that contain sufficient quantity of metals are called Ores They are the primary source of metals and other valuable materials used in various industries. Therefore all ores are minerals but all minerals are not ores. For example :Haematite is the ore of iron, Bauxite is the of Aluminium ,Copper pyrites is ores of the copper .
Metal :The elements which have  a tendency to loss electrons and form cat ion are called metal .For example :Mg, Na, Ca, Al etc.
Properties of metals:
Physical properties:
i)Most of metals are solid at ordinary temperature ,except mercury ,it is found in liquid state .
ii)Most of metals are generally hard ,except Na, K, Li, they are soft .
iii)Metal posses metallic luster (shining)
iv)Metals have generally high density ,except Na, K ,Li.
v)Metal posses ductile property (i.e. can be change into wires)except Na, K, Li.
vi)Metals are generally good conductors of heat and electricity .
vii)The boiling and melting point of metals are high ,except Na, K, Li.
viii)Metals atoms generally contains 1,2,3,electrons to their valence shell .
ix)Metals are generally electropositive in nature because loss their valence electrons.
x)Metals possess malleability (i.e. can be beaten in thin plate)
Non metal :The element which have a tendency to loss electrons and form anions are called non metal .For example :H_{2 ,}O_{2 ,}Cl_2, Br_2, N₂ etc.
Properties :
i)Non metals are generally found in all three states i.e. solid For example: Carbon ,liquid For example: Bromine ,gas For example :Hydrogen ,Oxygen, Nitrogen etc.
ii)Non metals are generally soft and light ,except carbon in the form of diamond and graphite .
iii)Non metals have generally very low melting points ,except carbon.
iv)Non metals have generally very low density ,except iodine.
v)Non metals are generally not ductile ,except carbon.
vi)Non metal are not malleable .
vii)Non metal are generally brittle (i.e. break  when force is applied )
viii)Non metals are non conductor of heat and electricity .
ix)Non metals generally contains 4 or more than 4 electrons to their valence shell.

Ores of some Metals:
1.)Iron
Symbol =Fe (Ferrum)
Atomic number (At .N.)=26
Atomic weight (At. Wt.)=56
Valency :2 (Ferrous)
                : 3 (Ferric)

Position in periodic table :Transition metal ,d-block elements ,4rth periods .
Ores :
i)Haematite (Fe₂O₃) : it is also called major ores of iron .

ii)Magnetite (Fe₃O₄)
iii)Iron carbonate (FeCO₃)
iv)Siderite(FeCO₃)
v)Limonite(2Fe₂O_3.3H₂O)
vi)Iron pyrite (FeS₂)
Physical properties :
i)It is shiny and grayish white metal .
ii)It is malleable and ductile .
iii)It is good conductor of heat and electricity
Uses :
i)It is used for making different types of pipes rods ,and cable wires .
ii)It is used for making different types instruments and weapons .
iii)It is used for making building ,bridges ,and means of transportation i.e. bus, trucks etc.
iv) It is used for making different types of household utensils .
v) It is used for making steels .
2.) Aluminium
Symbol =Al (Aluminium)
Atomic number (At .N.)=13
Atomic weight (At. Wt.)=27
Valency :3

Position in periodic table : Group -IIIA ,P-block elements ,3rth periods .
Ores :
i)Bauxite =Al₂O_3.2H₂O :It is also called major ores of Aluminium.

ii)Felspar =K((AlSiO_3.O₈)
iii)Cryolite(Na₃AlF₆)
iv)Kaolin(Al₂Si₂O₇2H₂O)
v) Corundum (Al₂O₃)
Physical properties :
i)It is shiny and silvery white metal .
ii)It is malleable and ductile .
iii)It is good conductor of heat and electricity
Uses :
i)It is used for making aluminium paint .
ii)It is used for making electric cable .
iii)It is used for making coins .
iv)Due to its malleable ,ductile and light properties it is used for making aeroplane .ship,car etc .
v)It is used for making household utensil  .
3.)Copper
Symbol =Cu (Cuprum)
Atomic number (At .N.)=29
Atomic weight (At. Wt.)=63.57
Valency :1 (Cuprous )
                 =2(Cupric)

Position in periodic table : Transition metal ,d-block elements ,4rth periods .
Ores :
i)Copper pyrite or chalcopyrite =CuFeS₂: it is also called major ore of copper .

ii)Chalcocite or copper glance =Cu₂S
iii)Cuprite (Ruby copper )
iv)Malachite
v)Azurite
Physical properties :
i)It is shiny and reddish brown metal .
ii)It is malleable and ductile .
iii)It is good conductor of heat and electricity.
 Uses:
i)It is used for making cables ,and electric appliances .
ii)It is used for making coins ,and brass .
iii)It is used for making household utensil.
iv)It is also used for making insecticide and pesticides .
4.)Silver
Symbol =Ag (Argentum)
Atomic number (At .N.)=47
Atomic weight (At. Wt.)=107.9
Valency :1

Position in periodic table : Transition metal ,d-block elements ,5^th  periods .
Ores :
i)Argentite or silver glance =Ag₂S: It is also called major ore of silver .

ii)Silver copper glance =(AgCu)₂S
iii)Horn silver (AgCl)
iv) Ruby silver (Ag₂Sb₂S₃) 
Physical properties :
i)It is shiny white metal .
ii)It is malleable and ductile .
iii)It is good conductor of heat and electricity.
Uses:
It is used for making valuable household utensil .
ii)It is used for making coins and jewelry .
iii)it is used for making negative in photography .
iv)It is used for silver plating .
 
 
4.)Gold
Symbol =Au (Aurum)
Atomic number (At .N.)=79
Atomic weight (At. Wt.)=197.2
Valency :1(Aurrous )
              = 3(Aurric)

Position in periodic table : Transition metal ,d-block elements ,6^th  periods .
Ores :Gold is mostly found free state in nature due to less reactive nature ,so it is also called noble gas, but some important ores of gold are :
i)Alluvial soil

ii)Calaverite=AuTe₂
Uses of gold :
i)It is used for making jewelry and coins .
ii)It is used for making medals .
iii)It is used for making status.
iv) It is used for gold plating .
Aquarejia :Mixture of 3 parts of Conc HCl and 1 parts of Conc H(NO₃)is  called aquarejia .It produce nascent
Some ores of metal in Nepal .
i)Iron :Lalitpur ,Bhojpur,chitwan, Pyuthan
ii)Copper =Udayapur ,Makwanpur
iii)Gold= Rapti river,Mustang ,Kathmandu
iv)Manesium =Udayapur
v)Lead =Lalitpur
vi)Bismuth =Makwanpur
vii)Cobalt :Palpa
viii)Calcium =Lalitpur ,Kathmandu
ix)Zinc =Lalitpur

Metallurgy :
The branch of science that deals the study of the science and technology of metals, their production, properties, and uses is called metallurgy .
Mining:
 The process of extracting valuable minerals or other geological materials from the Earth is called  mining .

Types of mining: There are two main types of mining:
1.) Surface mining: The mining which  is done by removing the surface of the Earth to get to the minerals or materials is called surface mining. This type of mining is often used for minerals that are found near the Earth surface, such as coal, sand, and gravel etc. 

2.)Underground mining: The  mining which is done by digging tunnels to reach the minerals or materials is called under ground mining. This type of mining is often used for minerals that are found deeper underground, such as gold, diamonds, and copper etc.

General steps of Metallurgy:
1.)Ore Extraction: In this step ores are diged from  the Earth's surface. 

2.Crushing and Grinding: The process of converting  a solid material into fine particles by rubbing or crushing is called grinding .In this step ores are  break down into smaller pieces. This is done using powerful crushers and grinding mills, turning the ore into a fine powder. 

3.Concentration: The process to separate the metal from the gangue, is called concentration. The powdered ore contains not just the desired metal but also unwanted impurities called gangue. So in this step the gangue are removed from metal by various techniques such as froth flotation, where the metal-rich particles stick to bubbles and float to the top, while the gangue sinks., magnetic separation  where by help of magnetic method unmagnetic substance are removed.

4.Oxidation : The chemical reaction of a metal with oxygen, resulting in the formation of a metal oxide is called oxidation. It is easy to extract metal from metal oxide so oxidation is done after concentration .it is done by two methods:
a) Roasting and Calcination: To prepare the metal for extraction, it's often heated in a controlled environment. This process, called roasting or calcination, To removes impurities and converts the metal into a more suitable form for reduction.

The process in which metal is converted into its oxide by heating it below its melting points in presence of excess of air is called roasting. For example: ZnS is convert into ZnO by roasting .
The process in which metal is converted into its oxide by strongly heating it below its melting points in absence of  of air is called calcinations. For example: Carbonates and hydroxide ores are converted in to their respective oxides by calcinations.

5.Reduction:

The process of reducing metallic oxide into metal by removing oxygen is called reduction . Reducing agent such as coal, coke, natural gas, carbon monoxide are used as reducing agents, leaving behind the pure metal. For example: ZnO is reduced by using carbon, Ag2O and HgO is reduced by heating, Na, K, Ca, Mg ,Al oxide are by electrolysis method.

6.Refining:  The  process of purifying about 90% a metal from their respective ores is called  refining .The extracted metal may still contain some impurities, so it undergoes further purification called refining. On the basis of the nature of the metal to purified  refining is done by two methods :
a) Distillation:
The  process of separating the components of a liquid mixture by heating it to a boil and then condensing the vapour into a liquid. The process is based on the different boiling points of the components of the mixture. if impurities or metals can be evaporated by boiling. The liquid with the lowest boiling point will vaporize first, and the vapour will then condense back into a liquid. This process can be repeated to further purify the liquid. 

b.)Electro refining:
The  process of purifying a metal by passing an electric current through a solution containing the metal ions is called Electro refining . The impure metal is used as the anode,and cathode is a thin sheet of pure metal. When the electric current is passed through the solution, the metal ions are attracted to the cathode and deposited on it, while the impurities remain in the solution. This process is used to purify a variety of metals, including copper, nickel, silver, and gold. It is a very effective way to remove impurities from metals and produce high-purity products.

7.Shaping and Forming: Finally, the purified metal is ready to be shaped into various forms, such as sheets, wires, or bars. This can be done through various processes like casting, rolling, forging, or extrusion. 

      Unit -18     Hydrocarbon  and its compounds

Organic chemistry :The branch of chemistry concerned with the compounds of carbon is called organic chemistry .
Inorganic chemistry: The branch of chemistry concerned with the compound of elements other than carbon is called inorganic compound .
Differences between organic and inorganic compound :

Organic compound
Inorganic compound
i.)The compounds of carbon other than oxides of carbon ,carbonates, bicarbonates, and carbides are called organic compounds .
 
ii.)Organic compounds having low melting and boiling points .
iii.)Organic compounds burn easily .i.e. Ghee, alcohol 
iv)These are formed by covalent bond.
v.)Organic compounds are insoluble in water .
i.)The compounds other than compounds of carbon except oxides of carbon, carbonates ,bicarbonates ,and carbides are called inorganic compounds.
ii.)Inorganic compounds having high melting and boiling points
iii)Inorganic compounds do not burn easily . i.e. salt
iv)These  are formed by electrovalent bond.
v)Inorganic compounds are soluble in water . Hydrocarbon :The chemical compounds which is formed by the bonding between Hydrogen and carbon is called Hydrocarbon .
Types of Hydrocarbon :-They are two types .
1)Saturated hydrocarbon :The hydrocarbon in which carbon –carbon atoms combine with single covalent bond is saturated hydrocarbon .Its IUPAC (International union pure applied chemistry )is Alkane or Paraffins .
Alkane or Paraffin :A hydrocarbon in which carbon – carbon atoms combine with single covalent bond is called Alkane or paraffin .Its general formula is  C_n H_2n +2 where n= number of carbon atoms i.e. 1,2,3,4 etc. For example :

B.)Unsaturated hydrocarbon :The hydrocarbon in which carbon atoms combine with double  or triple covalent bond is called unsaturated hydrocarbon.Its  IUPAC (International union pure applied chemistry ) name is Alkene   and  Alkyne  .
Alkene  or  Olefins :A hydrocarbon in which carbon –carbon atoms combine with double covalent bond is called  alkene or olefins .For example :

Alkyne or Acetylene : A hydrocarbon  in which carbon –carbon atoms combine with triple covalent is called alkyne or acetylene .For example :

Catenation: The ability of carbon to combine with another carbon atoms to long chain of or ring of different size is called catenation .For example :

Allotropes :The property of a pure element having same composition but found in two or more than two forms in the same state is called allotropes .For example :

Homologous series :A group of hydrocarbon which contains the same functional group but  has the different CH₂ group or length is called homologous series For example : Homologous series of alkane i.e.
Methane
Ethane 
Propane
Butane
Pentane
Homologous series of Alkene i.e.
Ethene
Propene
Butene
Pentene
Hexene
Properties of homologous series :
i)All members of homologous series can be represented by the same general formula .
ii)All member of homologous series show similar chemical properties .
iii)All the members of homologous series can be prepared by similar method .
Isomers :Isomers are the organic compound having the same molecular formula but different structure and properties are called isomers .The process of existence of two or more organic compound having same molecular formula but different structure and properties is called isomerism .For example :
i)CH₃CH₂OH                           CH₃-O-CH₃
Ethyl alcohol                           Dimethyl ether
ii)CH₃-O-C₃H₇                                   C₂H₅-O-C₂H₅
     Methyl propyl ether          Diethyl ether
Properties of isomers :
i)Isomers have same molecular formula .
ii)Isomers have different structural formula
iii)Isomers have different physical and chemical properties .
Alkyl radical :The group of organic compound which is formed by removing  one hydrogen atoms from alkane For example :
i)CH_4⟶            ^-H           CH₃⁺   (Methyl radical )
ii)C₂H₆  ⟶                  ^-H       C₂H₅⁺   (Ethyl radical)
When alkyl group combine with functional group and form different types organic compounds .For example :
i)CH₃OH    (Methyl alcohol )
ii)C₂H₅-O-C₂H₅       (diethyl ether )
Functional group: An atom or group of atoms that determine the chemical properties of a hydrocarbon is called a functional group . For example : i)Hydroxyl -(OH) =formed alcohol ii)-O- Formed ether 
 When alkyl group combine with functional group and form different types of organic compound .

Some important hydrocarbon and their uses ;
A)Methane =CH₄
It is saturated hydrocarbon and formed during decomposition of organic matter i.e.vegetable ,animals matters .It is also called Marsh gas .It is found in marshy or swamp areas and natural gas and petroleum mine  .
Uses :
i)It is used as source of  fuel .
ii) It is used for making water gas and hydrogen gas .
iii)It is used making printing ink and paints .
iv) It is used for making chloroform, carbon tetrachloride ,methyl alcohol.
B)Ethane =C₂H₆
It is saturated hydrocarbon .It is found in natural gas ,coal and petroleum mine .
Uses:
i)It is used as source of fuel .
ii)It is used for making shoe polish, printer ink.
C)Propane = C₃H₈
It is a saturated hydrocarbon .It is found in natural gas ,and petroleum mines .
Uses : i)It is used as source of fuel .i.e.  in lighter.
ii)It is used in petroleum industries for cooling purpose .
D)Butane  =C₄H₁₀
It is saturated hydrocarbon .It is found in natural gas and petroleum mine .
i)It is used as source of fuel i.e. LPG (Liquefied petroleum gas)
ii)It is used for making raw material for making synthetic rubber .
E) Alcohol:  Organic compound having hydroxyl group (OH) is called alcohol . For example : Methyl alcohol , Ethyl alcohol etc .
Types of alcohol : On the basis of number of hydroxyl groups .They are 3 types :
1.)Monohydric alcohol :The alcohol which is formed replacement of single hydrogen atom of alkane by same number of hydroxyl group is called monohydric alcohol .For example :

2.)Di hydric alcohol : The alcohol which is formed replacement of two hydrogen atom of alkane by  same number of hydroxyl group is called dihydric  alcohol .For example :

3.)Tri hydric alcohol : The alcohol which is formed replacement of three hydrogen atom of alkane by  same number of hydroxyl group is called tri hydric alcohol .For example :

Example of some monohydric alcohol :

Some important alcohol :
1.)Methyl alcohol =CH₃OH
Uses :i)It is used as fuel in sprit lamp (Produce heat without smoke )
ii)It is used for making synthetic fibre.
iii)It is used to dissolve fat, oil  paints ,varnish .
Note: Consumption of methyl alcohol causes of blindness or death .
2.)Ethyl alcohol =C₂H₅OH :It is also called real alcohol .
Uses : i) It is used for making intoxicated drinks i.e. wine, beer, whisky etc.
ii)It is used in alcohol thermometer.
iii)It is used for making medicine, soap, synthetic rubber etc.
iv)It is used as preservatives for biological specimens .
Note :Consumption of ethyl alcohol  causes of effects  cerebellum so person losses balance .
3.)Glycerol =C₃H₅(OH)₃: The word glycerol derived Latin word   glyceros ,which means sweet , so it is also called colourless viscous liquid with sweet taste .
Uses :It is used as sweetening  agent .
ii) It is used for making medicine .
iii)it is used for making stamp pad ink .
iv)It is used for making high quality of soap, cosmetics lotions ,creams etc.
F) Glucose :The glucose word has been derived from Greek word glukus which means sweets in taste .Its molecular formula is C₆H₁₂O₆ .It is also called dextrose .It is used used by body to produce ATP .it is found in fruit and honey .Glucose is both harmful and useful for animals .
Uses : It is used for prepare Bakelite plastic .
ii)It is used as sterilizing agent .
iii)It is used for making formalin which is used as a preservative for biological specimen

Unit -19
                 Chemicals used in Daily Life

 A. Food Preservatives :The substances which are added to food to extend their shelf life by inhibiting the growth of bacteria, yeast, mold, and other microorganisms that can cause spoilage(Sadna), deterioration(bigrina), discoloration(ranghin), and and help to enhance flavour(swad bdhauna) are called Food preservatives .They help maintain the quality, freshness, and safety of food by preventing or slowing down the natural processes of deterioration. They essentially extend the shelf life of food products, making them available for consumption for a longer period.
The example of some common food preservatives are:
1.Salt: It is a oldest and most effective preservatives, salt inhibits the growth of bacteria by dehydrating them.

2.Sugar: Sugar can also inhibit bacterial growth by creating a hypertonic environment,( by reducing the water content of foods, which inhibits microbial growth)where bacteria struggle to survive.

3.Vinegar: The acetic acid in vinegar inhibits the growth of bacteria and gives food a tangy flavor.

4.Citric acid: Citric acid is a naturally occurring compound found in citrus fruits. It inhibits the growth of bacteria and fungi.

5.Sulfur dioxide: Sulfur dioxide is widely used as a preservative in dried fruits, fruit juices, and wine. It helps prevent discoloration and inhibits the growth of bacteria, yeasts, and molds.

6.Sodium benzoate: Sodium benzoate is a common preservative used in acidic foods such as carbonated drinks, fruit juices, and pickles. It inhibits the growth of bacteria, yeasts, and molds.

7.Potassium sorbate: Potassium sorbate is used to inhibit the growth of molds, yeasts, and certain bacteria. It is commonly used in cheese, baked goods, and dried meat products.

8.Nitrites and nitrates: Nitrites and nitrates are commonly used in cured  meats (dry) like bacon, ham, and sausages. They help prevent the growth of bacteria, particularly Clostridium botulinum, which can cause botulism(disease caused by a toxin that attacks the body's nerves         

9.Probiotics: Live bacteria that can help to inhibit the growth of harmful bacteria.

Types of food preservatives :There are 3 types of food preservatives :

1.Chemical food preservatives:  The chemical  substances which are  added to food products to extend their shelf life, inhibit the growth of microorganisms, and prevent spoilage are called Chemical food preservatives. These preservatives help maintain the quality, freshness, and safety of food by preventing the growth of bacteria, yeasts, molds, and other pathogens (an organism causing disease) .For example :

i.Sodium Benzoate

ii.Potassium Sorbate

iii.Sodium Nitrite

iv.Sulfur Dioxide

v.Propionic Acid and its salts (calcium propionate, sodium propionate): These preservatives are commonly used in bread and other baked goods to prevent the growth of molds and extend shelf life.

vi.Benzoic Acid and its salts (sodium benzoate, potassium benzoate): They are used in a wide range of products, including soft drinks, fruit juices, and pickles, to inhibit the growth of bacteria, yeasts, and molds.

2.Natural Food preservatives : Natural food preservatives are the substances derived from natural sources which are added to food products to extend to  their shelf life, inhibit the growth of microorganisms, and prevent spoilage are called the shelf life of food products are called natural preservatives .

i.Vinegar:

ii.Salt

iii.Sugar:

iv.Citric Acid:

v.Vitamin E (Tocopherol): Vitamin E is a natural antioxidant that can help delay the oxidation of fats and oils. It is often used in food products that contain oils.

vi..Clove Oil: Clove oil has strong antimicrobial properties and can be used as a natural food preservative. It is particularly effective against fungi and molds (fungi). Clove oil is used in some meat products and baked goods.

3.Induced ripening fruits foods preservatives : Induced ripening of fruits refers to the process of accelerating the natural ripening of fruits using various methods are called Induced ripening fruits . There are certain substances and techniques  are used in to the  induce ripening in fruits are called Induced ripening fruits foods preservatives .For example:

i.Ethylene Gas: Ethylene is a natural plant hormone that regulates fruit ripening. It is commonly used to induce ripening in fruits like bananas, mangoes, and avocados. Fruits can be exposed to ethylene gas in controlled environments to speed up the ripening process.

ii.Calcium Carbide: Calcium carbide is a chemical compound that produces acetylene gas when it comes into contact with moisture. Acetylene gas has similar effects to ethylene and can be used to induce ripening in fruits.

Importance of food preservatives:
1.Preservatives help food to prevent from spoilage caused by bacteria ,molds (large group of fungus), fungus  and Yeasts .
2.Preservatives can keep food fresher for longer time periods ,extending its shelf life.
3.Food preservatives help to slow or prevent changes of colour ,flavour, and delay rancidity.
Harmful effects Food preservatives:
1.High sodium product like pickle can causes of higher blood pressure.
2.Canned food does not taste as a good food as fresh food because canned food has lower nutritional value than that of fresh food. For example : Canned fruit and vegetables have 65% less vitamins and minerals than fleshy fruit and vegetables .
3.Artificial preservatives such as nitrates ,benzoates ,sorbatees etc can causes of serious health hazards such as allergy, asthma, hyperactivity, hypersensitivity .
4.Long term consumption of preserved food causes of obesity (excessive fat).
 
B.Introductions and uses of chemicals used in cleansing:
1. Rittha :It is a herb, also known as soapnut or Indian soap berry, has a long history of traditional use for cleansing purposes in various cultures.

Advantages:
i.Natural cleansing: Rittha contains saponins, natural foaming agents that gently cleanse the skin and hair.
ii. It help to protect skin from acne(dry), dandruff, and eczema. 
iii. Hair conditioning: Rittha's lather can act as a natural conditioner, leaving hair soft and manageable.
iv. Hair wash: boiling the fruits in water and use the liquid as a natural hair shampoo.
v. Skin cleanser: Rittha paste by grinding the fruits and mix it with water for a gentle face wash or body scrub.
iv. Laundry detergent: Rittha can be used as a natural alternative to conventional laundry detergent.
2.Mustard paste: . Mustard seeds contain essential B-complex vitamins such as folate, niacin, thiamin and vitamin B6, which are very useful for the overall health, cleanliness and growth of hair.

Advantages:
i.Mustard  paste is used to clean the hair, make the hair soft and strong.
ii. Mustard paste is used to prevents hair loss to a large extent.
iii. Its makes the hair soft and nourished.
3.Ash:
The paste of wood ash is  used in cleansing. It is mixed with a small amount of water to make a paste.

Advantages:
i.The paste of ash is used as an abrasive cleaner.
ii.It is used to shines metals, cleans dirty dishes and also removes stubborn dirt and oil.
iii. Wood ash is also a good source of potassium, phosphorus and magnesium for plants.
4.Sajivan:
Sajivan is a multipurpose plant that has been naturally produced in various parts of Nepal. It has been used in various ways in Nepal. This plant is not eaten by domestic animals.

Advantages:
i.it is used to make fences(khet bari ko bsr) in the fields.
ii. Its leaves are used to make compost.
iii. Its juice is used to heal burns, as an anti-cancer drug.
iv. Its  stem of a small branch is used to clean teeth.
v. its leaves are used as organic fertilizers containing very good nitrogen, phosphorus and potash.
C.) Soap and Detergent :
Soap :The sodium salt of long chain of fatty acid having cleansing properties in water  is called soap . For example :i)Sodium stearate (C₁₇H₃₅COONa)    ii)Sodium Oleate (C₁₇H₃₃COONa),     iii) Sodium Palmitate (C₁₇H₃₁COONa)

It is prepared by heating fat or oil with sodium hydroxide solution .

The process of making soap by hydrolysis of fat or oil with sodium hydroxide or alkali is called  saponification .

Detergents :Synthetic petrochemical obtained from hydrocarbon which is more soluble than soap is called detergent .It is more soluble and useful than that of salt .Detergent possess  cleansing properties similar to the soap but they are not chemically soap therefore detergents are also called soapless  soap .For example :i)Sodium lauryl sulphate    ii) Alkyl benzene sulphonate  iii)Sodium pyrophosphate .

Due to following reasons detergent is better than that of salts :
i)Detergent clean more effectively in hard water than that of soap .
ii)It maintains its cleansing power better than that of soap over long period of time .
iii)It is more soluble in water than that soap .
iv) It also help to save vegetable oil for human consumption .
Washing powder  :A synthetic powder having cleansing properties containing synthetic detergent about 15%-30% is called washing powder
Differences between Soap and Detergent

Soap	Detergent
i)It is prepared from animals  fat or plants oil . ii)It is sodium salt of long chain of fatty acid . iii)It has weak cleansing properties . iv)it is very less soluble in hard water . v)It is bio-degradable . v)For example :Sodium stearate	i)It is prepared from hydrocarbon of petroleum . ii)It is sodium salt of long chain of benzene sulphonic acid . iii)It is has strong cleansing properties . iv)It is soluble in hard water . v)It is non bio-degradable . vi) For example :Sodium lauryl sulphonate.

Harmful effects of chemical cleansing:
1.Respiratory irritation: Many cleaning products,  like bleach and ammonia, release fumes that can irritate the lungs, eyes, and throat. This can lead to coughing, wheezing, and  asthma
2.Skin and eye damage: Direct contact with cleansing chemicals can cause skin burns, rashes, and allergic reactions. 
3.Long-term health effects: Some chemicals used in cleaning products can causes more serious health problems, such as cancer, reproductive issues, and nervous system damage. 
4.Water pollution: Chemicals from cleaning products can harm aquatic life and disrupt ecosystems.
5.Climate change: The production and transportation of cleaning chemicals often involve greenhouse gas emissions, contributing to climate change.
6.Corrosion: Some cleaning products are highly corrosive(strong) and can damage surfaces, and discoloration especially metals and wood.
D.Chemical Pesticides : The mixture of chemicals substances which are used for preventing, destroying or controlling   any  unwanted organisms/pests such as Insects (mosquitoes, ants, termites, beetles), Plant pathogens(fungi, bacteria, viruses),Weeds( unwanted plants
Rodents(mice, rats) and Other organisms( molluscs, birds, mammals) 
 are called pesticides.
Types of Pesticides:
A.On the basis of  Environments: They are 2 types :
(i) Environmentally degradable or non persistent:
The  pesticides that gradually decay after coming in contact with environmental components such as water, air, light, heat, etc are called Environmentally degradable or non persistent pesticides. For example: Dimethoate (Nugar, Roger, Dimet), Malathayan etc.

(ii) Environmentally non-degradable or persistent: The Pesticides that do not decay after coming in contact with environmental components such as water, air, light, heat etc and remain in our body mixed with fat through the food chain are called Environmentally non-degradable or persistent Pesticides. Import, export, sale and use of Pesticides of this group have been banned in most countries.For Example:DDT (Dichloro diphenyl trichrolo ethane),BHC(Benzene Hexa chloride),Aldrine ,Dialdrine .

B.On the basis of target organisms :They are 5 types :
(i) Insecticides :The Pesticides which are  used to control harmful  insects are called insecticides For example: Malathion, cypermethrin, fenbalarate, nitenpyram etc.

(ii) Fungicides :The Pesticides which are used to against various types of fungal diseases in plants  are called Fungicides such as: Dimethomorph, Sectin, Mancozeb, Carbendazim etc.

(iii) Herbicides: The Pesticides which are used to kill various types of weeds that attack crops are called Herbicides .such as Butachlor, Isoproteron, Atrazine etc.

(iv) Rodenticides: The Pesticides which are used to kill harmful animals such as rats and mice, rats, mice, rats, rabbits, etc are called Rodenticides. For example Kimateraline, Phosphide .

(v) Miticides: The Pesticides which are used to kill mites are called Miticides. For example :Bifenazet, Phenazaquone, Proparzite, Fenpyroximate etc.

C.On the basis of nature and action: They are 4 types :
(i) Contact pesticide:The pesticides which are to kill the Insects with soft bodies such as larvae, thrips, whiteflies etc. come in direct contact with the outer covering are called contact pesticide .For example: Malathien, chloropyrifus etc.

(ii) Stomach pesticide:The pesticides which are used to kill the insect when the insects eat the leaves or fruits of the poisoned plants are called Stomach pesticides .Forexamle:  malathion, cypermethrin, fenvalerate etc.

(iii) Systemic pesticide :The pesticides which are used to kill the insects such as  Lahi, Thrips, White Binga, Leaf Miner, Gabaro by sucking the juice of poisonous plants, are called systemic pesticides etc. For control, Folithion, Biomultinim, Multinim etc. In this process  the leaves or roots of the plant absorb the poison, as a result, the poison reaches the entire part and the plant itself becomes toxic.

(iv) Fumigants pesticide: The pesticides when  come in contact with the air, poisonous gases are released due to which the insects die. These types of pesticides are called Fumigants pesticide. For example : aluminum phosphide, methyl bromide, etc.

Advantages of Pesticides :
i.It help to save the farmer by protecting crops from insects and other pests .
ii.It help to controlling pests and plants diseases .
iii.It help to control human /livestock diseases .
iv.It help to control organisms that harm  human activities.
Effects of Pesticides :
i.Environmental Impact: Pesticides can contaminate soil, water bodies, and air, and also can harm non-target organisms, such as beneficial insects, birds, fish, and amphibians, disrupting ecosystems and reducing biodiversity.
ii.Health Risks for Humans: Pesticides can effects, in skin ,and causes of  eye irritation, respiratory problems, neurological disorders, reproductive issues, and even certain types of cancer.
iii.Water Pollution: Pesticides can, contaminate drinking water sources and aquatic environments. This contamination can harm aquatic organisms, disrupt ecosystems.
iv.Residue in Food: Pesticide residues can remain  in food crops. Consuming food with pesticide residues, particularly in high amounts over an extended period, can potentially have adverse health effects.
v.Disruption of Natural Pest Control: Pesticides not only target pests but also affect beneficial organisms that naturally control pest populations.
Safely precautions in the use and storage of the pesticides :
The following precautions must be taken when storing and using chemical pesticides:
(i) Pesticides should be imported, produced, bought and used only as prescribed by the Pesticides Management Act, 2076 and regulations.
(ii) Pesticides should be purchased only according to the consultation of the agricultural technician.
(iii) The name should be clearly identified on the container where the pesticide is kept.
(iv)  Storing pesticides should not be kept close to children's access and food.
(v) Pesticides should be kept tightly closed in airtight and leak-proof containers.
(vi) When using pesticides, the instructions written on the label (indicator letter) of the pesticide should be read carefully and used only.
(vii) Equipment used for spraying pesticides should be cleaned immediately and kept in a safe place.
 (viii) Crops (vegetables and fruits) should not be sold or consumed immediately after using pesticides.
E.Chemical pollution :The environmental degradation due to unscientific and improper uses of chemical substances is called chemical pollution .
Causes of chemical pollution :
1.)Uses of insecticides and chemical fertilizer :It causes of air ,water and soil pollution ,different diseases ,the death of fishes and other aquatic life .
2.)Household wastage and plastics :The toxic substances present in wastage causes of air ,water ,and soil pollution and produce poisonous gases burning .
3.)Uses of coloring materials in food stuff :It  causes of dangerous diseases i.e. cancer .
4.)Products of smokes vehicles  and industries :It causes of air pollution of air and different diseases .
5.)Uses of synthetic cleaner (detergent ):It causes of rapid growth of weeds and algae in water due to lack of oxygen in water as result aquatic animals begin to die .
Methods of controls of chemical pollution :
i)By scientific and proper uses of insecticides and fertilizer .
ii)By management of household wastages and plastics .
iii)By management of smoke produce  by vehicles and industries .
iv)By less uses of coloring materials in food stuff .
v)By management of uses of synthetic cleaner .