CLASS 10 - SCIENCE
FORMULA BOOK
FOR CBSE BOARD
1. CHEMICAL REACTIONS AND EQUATIONS When a substance is decomposed by absorbing
light energy, it is called photodecomposition
h h Characteristics of Chemical Reactions : reaction or simply photolysis.
Sunlight
–– change in state 2AgCl(s) 2Ag(s) + Cl2(g)
–– change in colour Silver chloride Silver Chlorine
(White) (Grey)
–– evolution of a gas
–– Displacement reactions :
–– change in temperature
The chemical reactions in which one element
–– formation of a precipitate
takes the position or place of another element
h h Types of Chemical Reactions : present in a compound are called displacement
–– Combination reactions : reactions.
When two or more substances (elements or These reactions occur mostly in solution form
compounds) combine to form a single product,
and a more active metal displaces or removes
the reactions are called combination reactions.
less active metal from its salt solution.
C(s) + O2(g) CO2(g)
Carbon Oxygen Carbon dioxide
Zn(s) + CuSO4(aq) ZnSO4(aq) + Cu(s)
Zinc Copper Zinc Copper
–– Decomposition reactions : sulphate sulphate
When a single reactant breaks down to give –– Double displacement reactions :
two or more simpler products, the reactions are Reactions in which there is an exchange of
called decomposition reactions. Decomposition ions between the reactants are called double
reactions require energy either in the form of displacement reactions.
heat, light or electricity for breaking down the
AgNO3(aq) + NaCl(aq) AgCl(s) + NaNO3(aq)
reactants.
Silver nitrate Sodium Silver chloride Sodium nitrate
When a decomposition reaction is carried out chloride (White ppt.)
by heating, it is called thermal decomposition
–– Precipitation reactions :
reaction.
Reaction that produces a precipitate is called a
CaCO3(s) Heat CaO(s) + CO2(g)
precipitation reaction.
Limestone Quick lime
The insoluble substance formed is known as a
When a substance in the molten state or in
precipitate.
aqueous solution is decomposed by passing
electric current, it is called electrolytic Pb(NO3)2(aq) + 2KI(aq) PbI2(s ) + 2KNO3(aq)
decomposition reaction or simply electrolysis. Lead Potassium Lead Potassium
nitrate iodide iodide nitrate
2H2O(l ) Electric 2H2(g) + O2(g) (Colourless) (Colourless) (Yellow ppt.)
current
Water Hydrogen Oxygen
Science 1
,h h Oxidation and reduction Reactions : Gain of oxygen
–– Reactions in which one reactant gets oxidised (Oxidation)
while the other gets reduced are called oxidation- Fe2O3 + 2Al 2Fe + Al2O3
reduction reactions or redox reactions. Loss of oxygen
–– Oxidation is defined as the addition of oxygen (Reduction)
to a substance or removal of hydrogen from a Fe2O3 Oxidising agent
substance in a chemical reaction. Al Reducing agent
–– Reduction is defined as the addition of h h Exothermic and Endothermic Reactions :
hydrogen to a substance or removal of oxygen
from a substance in a chemical reaction. –– Exothermic reactions : Reactions in which heat
–– The substance which either gives oxygen or is released along with the formation of products
gains hydrogen in a reaction, is known as an are called exothermic reactions.
oxidising agent. –– Endothermic reactions : Reactions in which
–– The substance which either gives hydrogen energy is absorbed during the chemical reaction
or gains oxygen in a reaction, is known as a are known as endothermic reactions.
reducing agent.
2. ACIDS, BASES AND SALTS
COLOURS OF SOME COMMON INDICATORS IN ACIDIC AND BASIC SOLUTIONS
Nature of Indicators
substance Blue litmus Red litmus Methyl orange Phenolphthalein Turmeric China rose Red cabbage
Acidic Red No change Red Colourless No change Dark pink Red
Basic No change Blue Yellow Pink Red Green Green
h h Chemical properties of Acids and Bases –– pH = 0-7, Acids
Metal + Dilute acid → Metal salt + Hydrogen –– pH = 7, Neutral
Metal carbonate/Metal hydrogencarbonate + Acid –– pH = 7-14, Bases
→ Salt + Carbon dioxide + Water Some Important Acids, Bases and Salts
Neutralization reaction : h h Sodium Hydroxide :
Base + Acid → Salt + Water –– Chemical formula : NaOH, Common name:
Metallic oxides are basic oxides : Caustic soda, Action on litmus : Turns red
Metal oxide + Acid → Salt + water litmus blue, Solubility : Soluble in water (Highly
Non-metallic oxides are acidic oxides alkaline)
Non-metallic oxide + Base Salt + Water h h Bleaching Powder :
h h pH scale –– Chemical formula : CaOCl2 (Actual composition
pH can be defined as logarithm of reciprocal of is quite complex), Chemical name : Calcium
H3O + ions in aqueous solution. oxychloride, Solubility : Soluble in water
or h h Baking Soda :
1 –– Chemical formula : NaHCO3, Chemical
pH = log or pH = –log [H3O +]
[H3O+ ] name : Sodium hydrogencarbonate or Sodium
or [H +] = 10 –pH bicarbonate, Action on litmus : Turns red litmus
In pH scale, less is the value of pH more is the acidic blue, Solubility : Sparingly soluble in water
nature of the substance. In pH scale : (Weakly basic)
2 Science
, h h Washing Soda : Name Formula
–– Chemical formula : Na2CO3·10H2O, Chemical Hydrated copper sulphate CuSO4 ·5H2O
name : Sodium carbonate decahydrate, Action Washing soda Na2CO3 ·10H2O
on litmus : Turns red litmus blue, Solubility : Gypsum CaSO4 ·2H2O
Sparingly soluble in water (Weakly basic)
Plaster of Paris CaSO4 · 1 H2O
h h Water of Crystallization : 2
Zinc sulphate ZnSO4 ·7H2O
–– It is the fixed number of water molecules present
in one formula unit of a salt. Magnesium sulphate MgSO4 ·7H2O
3. METALS AND NON-METALS
COMPARISON OF PHYSICAL PROPERTIES OF METALS AND NON-METALS
Property Metals Non-metals
Physical state Metals are generally solids (except Non-metals (except bromine which is a
mercury and gallium which are liquids) liquid) are either solids or gases at room
at room temperature. temperature.
Lustre Metals have lustre and can also be Non-metals (except iodine and graphite) do
polished. not have lustre and also cannot be polished.
Hardness Metals (except lithium, sodium and Non-metals (except diamond and boron) are
potassium) are generally hard. generally soft.
Malleability and Metals are malleable (can be hammered Non-metals are neither malleable nor ductile.
ductility into thin sheets) and ductile (can be They are actually brittle.
drawn into wires).
Melting points Metals (except mercury and gallium) Non-metals (except graphite and boron) have
and boiling points generally have high melting and boiling low melting and boiling points.
points.
Density Metals generally have high densities. Non-metals generally have low densities.
Conductivity Metals are good conductors of heat Non-metals (except graphite and gas carbon)
and electricity. are bad conductors of heat and electricity.
Sonorosity Metals are sonorous ( i.e ., produce Non-metals are non-sonorous ( i.e ., do not
sound when hit with a hard object). produce any sound when hit with a hard object).
COMPARISON OF CHEMICAL PROPERTIES OF METALS AND NON-METALS
Property Metals Non-metals
Nature of ions Metals are electropositive elements and Non-metals are electronegative elements and
hence, lose one or more electrons to form hence, gain one or more electrons to form
positive ions. negative ions.
Nature of Metals mostly form basic oxides. Some Non-metals form either acidic or neutral oxides.
oxides metals such as Zn and Al form amphoteric
oxides.
Reaction with Most of the metals displace hydrogen Non-metals (except fluorine) generally do not
water from water or steam. react with water or steam.
Science 3
FORMULA BOOK
FOR CBSE BOARD
1. CHEMICAL REACTIONS AND EQUATIONS When a substance is decomposed by absorbing
light energy, it is called photodecomposition
h h Characteristics of Chemical Reactions : reaction or simply photolysis.
Sunlight
–– change in state 2AgCl(s) 2Ag(s) + Cl2(g)
–– change in colour Silver chloride Silver Chlorine
(White) (Grey)
–– evolution of a gas
–– Displacement reactions :
–– change in temperature
The chemical reactions in which one element
–– formation of a precipitate
takes the position or place of another element
h h Types of Chemical Reactions : present in a compound are called displacement
–– Combination reactions : reactions.
When two or more substances (elements or These reactions occur mostly in solution form
compounds) combine to form a single product,
and a more active metal displaces or removes
the reactions are called combination reactions.
less active metal from its salt solution.
C(s) + O2(g) CO2(g)
Carbon Oxygen Carbon dioxide
Zn(s) + CuSO4(aq) ZnSO4(aq) + Cu(s)
Zinc Copper Zinc Copper
–– Decomposition reactions : sulphate sulphate
When a single reactant breaks down to give –– Double displacement reactions :
two or more simpler products, the reactions are Reactions in which there is an exchange of
called decomposition reactions. Decomposition ions between the reactants are called double
reactions require energy either in the form of displacement reactions.
heat, light or electricity for breaking down the
AgNO3(aq) + NaCl(aq) AgCl(s) + NaNO3(aq)
reactants.
Silver nitrate Sodium Silver chloride Sodium nitrate
When a decomposition reaction is carried out chloride (White ppt.)
by heating, it is called thermal decomposition
–– Precipitation reactions :
reaction.
Reaction that produces a precipitate is called a
CaCO3(s) Heat CaO(s) + CO2(g)
precipitation reaction.
Limestone Quick lime
The insoluble substance formed is known as a
When a substance in the molten state or in
precipitate.
aqueous solution is decomposed by passing
electric current, it is called electrolytic Pb(NO3)2(aq) + 2KI(aq) PbI2(s ) + 2KNO3(aq)
decomposition reaction or simply electrolysis. Lead Potassium Lead Potassium
nitrate iodide iodide nitrate
2H2O(l ) Electric 2H2(g) + O2(g) (Colourless) (Colourless) (Yellow ppt.)
current
Water Hydrogen Oxygen
Science 1
,h h Oxidation and reduction Reactions : Gain of oxygen
–– Reactions in which one reactant gets oxidised (Oxidation)
while the other gets reduced are called oxidation- Fe2O3 + 2Al 2Fe + Al2O3
reduction reactions or redox reactions. Loss of oxygen
–– Oxidation is defined as the addition of oxygen (Reduction)
to a substance or removal of hydrogen from a Fe2O3 Oxidising agent
substance in a chemical reaction. Al Reducing agent
–– Reduction is defined as the addition of h h Exothermic and Endothermic Reactions :
hydrogen to a substance or removal of oxygen
from a substance in a chemical reaction. –– Exothermic reactions : Reactions in which heat
–– The substance which either gives oxygen or is released along with the formation of products
gains hydrogen in a reaction, is known as an are called exothermic reactions.
oxidising agent. –– Endothermic reactions : Reactions in which
–– The substance which either gives hydrogen energy is absorbed during the chemical reaction
or gains oxygen in a reaction, is known as a are known as endothermic reactions.
reducing agent.
2. ACIDS, BASES AND SALTS
COLOURS OF SOME COMMON INDICATORS IN ACIDIC AND BASIC SOLUTIONS
Nature of Indicators
substance Blue litmus Red litmus Methyl orange Phenolphthalein Turmeric China rose Red cabbage
Acidic Red No change Red Colourless No change Dark pink Red
Basic No change Blue Yellow Pink Red Green Green
h h Chemical properties of Acids and Bases –– pH = 0-7, Acids
Metal + Dilute acid → Metal salt + Hydrogen –– pH = 7, Neutral
Metal carbonate/Metal hydrogencarbonate + Acid –– pH = 7-14, Bases
→ Salt + Carbon dioxide + Water Some Important Acids, Bases and Salts
Neutralization reaction : h h Sodium Hydroxide :
Base + Acid → Salt + Water –– Chemical formula : NaOH, Common name:
Metallic oxides are basic oxides : Caustic soda, Action on litmus : Turns red
Metal oxide + Acid → Salt + water litmus blue, Solubility : Soluble in water (Highly
Non-metallic oxides are acidic oxides alkaline)
Non-metallic oxide + Base Salt + Water h h Bleaching Powder :
h h pH scale –– Chemical formula : CaOCl2 (Actual composition
pH can be defined as logarithm of reciprocal of is quite complex), Chemical name : Calcium
H3O + ions in aqueous solution. oxychloride, Solubility : Soluble in water
or h h Baking Soda :
1 –– Chemical formula : NaHCO3, Chemical
pH = log or pH = –log [H3O +]
[H3O+ ] name : Sodium hydrogencarbonate or Sodium
or [H +] = 10 –pH bicarbonate, Action on litmus : Turns red litmus
In pH scale, less is the value of pH more is the acidic blue, Solubility : Sparingly soluble in water
nature of the substance. In pH scale : (Weakly basic)
2 Science
, h h Washing Soda : Name Formula
–– Chemical formula : Na2CO3·10H2O, Chemical Hydrated copper sulphate CuSO4 ·5H2O
name : Sodium carbonate decahydrate, Action Washing soda Na2CO3 ·10H2O
on litmus : Turns red litmus blue, Solubility : Gypsum CaSO4 ·2H2O
Sparingly soluble in water (Weakly basic)
Plaster of Paris CaSO4 · 1 H2O
h h Water of Crystallization : 2
Zinc sulphate ZnSO4 ·7H2O
–– It is the fixed number of water molecules present
in one formula unit of a salt. Magnesium sulphate MgSO4 ·7H2O
3. METALS AND NON-METALS
COMPARISON OF PHYSICAL PROPERTIES OF METALS AND NON-METALS
Property Metals Non-metals
Physical state Metals are generally solids (except Non-metals (except bromine which is a
mercury and gallium which are liquids) liquid) are either solids or gases at room
at room temperature. temperature.
Lustre Metals have lustre and can also be Non-metals (except iodine and graphite) do
polished. not have lustre and also cannot be polished.
Hardness Metals (except lithium, sodium and Non-metals (except diamond and boron) are
potassium) are generally hard. generally soft.
Malleability and Metals are malleable (can be hammered Non-metals are neither malleable nor ductile.
ductility into thin sheets) and ductile (can be They are actually brittle.
drawn into wires).
Melting points Metals (except mercury and gallium) Non-metals (except graphite and boron) have
and boiling points generally have high melting and boiling low melting and boiling points.
points.
Density Metals generally have high densities. Non-metals generally have low densities.
Conductivity Metals are good conductors of heat Non-metals (except graphite and gas carbon)
and electricity. are bad conductors of heat and electricity.
Sonorosity Metals are sonorous ( i.e ., produce Non-metals are non-sonorous ( i.e ., do not
sound when hit with a hard object). produce any sound when hit with a hard object).
COMPARISON OF CHEMICAL PROPERTIES OF METALS AND NON-METALS
Property Metals Non-metals
Nature of ions Metals are electropositive elements and Non-metals are electronegative elements and
hence, lose one or more electrons to form hence, gain one or more electrons to form
positive ions. negative ions.
Nature of Metals mostly form basic oxides. Some Non-metals form either acidic or neutral oxides.
oxides metals such as Zn and Al form amphoteric
oxides.
Reaction with Most of the metals displace hydrogen Non-metals (except fluorine) generally do not
water from water or steam. react with water or steam.
Science 3
