2. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Lesson Objectives
After completing this lesson
you will be able to classify
the chemical reaction and
identify the type of chemical
After completing this lesson you will be able to reaction.
• classify the chemical reaction
• identify the type of chemical reaction
3. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
In a chemical reaction , a
reactant and a reagent combine
and form a new product and a
by-product.
Reactant + Reagent Product + By-product
4. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Let us watch this reaction.
What happens in this reaction?
5. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Magnesium ribbon burns in air
to become magnesium oxide.
2Mg + O2 2MgO
Magnesium Magnesium oxide
6. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
We can classify reactions into
combination reaction,
displacement reaction,
Types of reactions decomposition reaction,
double displacement reaction,
neutralisation reaction, red-ox
Combination reaction reactions, thermal dissociation
Displacement reaction reaction and irreversible and
irreversible reactions.
Decomposition reaction
Double displacement reaction
Neutralisation reaction
Oxidation - reduction reaction
Thermal dissociation reaction
Reversible and irreversible reaction
7. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Combination Reaction In this simple combination
reaction, magnesium
combines with oxygen to form
magnesium oxide.
2Mg + O2 2MgO
Magnesium ribbon
Magnesium oxide powder
8. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Interactivity
Click the view answer button
to find out the product.
Na + Cl2 ? (on heating)
What could be the product?
View answer
9. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Sodium and chlorine combine
on heating to form sodium
Heat chloride.
2 Na + Cl2 2 NaCl
Sodium metal Chlorine gas Sodium chloride
10. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Sulphur combines with iron on
heating to give iron sulphide.
Fe + S FeS
Iron Iron powder
Sulphur
powder
Mixing iron Iron sulphide powder
and sulphur
11. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Let us see some more
examples of combination
reaction. Nitrogen combines
with hydrogen and gives
ammonia on heating. Similarly
sulphur combines with oxygen
Heat to form sulphur dioxide.
N2 + 3H2 2NH3
S + O2 SO2
12. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Interactivity
Click on the view answer
button to find out the product.
Complete the reactions
H2 + Cl2 __?__
View answer
13. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Hydrogen and chlorine
combine to form hydrogen
chloride.
H2 + Cl2 2HCl
14. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Displacement Reaction We can classify displacement
reactions further into metal-
metal displacement and
metal-nonmetal displacement
Displacement Reaction reactions.
Metal-metal Metal - non-metal
15. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Metal – Metal Displacement According to reactivity series
the most reactive metals
replace the less reactive
metals.
16. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Interactivity
Click the view answer button
to find out the product.
Complete the reaction
Cu + AgNO3 _____ + _____
View answer
17. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Since copper is more reactive
Cu + 2AgNO3 2Ag + Cu(NO3)2 than silver copper replaces
silver in this reaction.
Copper coil
Silver nitrate solution Silver and copper nitrate solution
18. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Metal – Non-metal Displacement Sometimes, a metal displaces
a non-metal. Different metals
have different reactivities with
various non-metals such as
2Na + 2H2O 2NaOH + H2 ↑ oxygen and hydrogen. For
example, sodium reacts
violently with water, even at
room temperature to replace
hydrogen, the non-metal.
Reaction of sodium with water
19. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Hydrogen in water is replaced
by magnesium only on
heating.
Heat
Mg + H2O MgO + H2 ↑
Magnesium powder Magnesium oxide
20. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Copper does not react with
Order of reactivity of metals with water water. Sodium is more
reactive with water. Thus we
can predict the non-metal
Na > Mg > Fe > Cu displacement by the order of
reactivity.
Reaction of sodium with water
21. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Interactivity
Click the view answer button
to find out the products.
Iron reacts with steam when it is red hot.
Complete the equation
Fe + H2O Red hot _____ + ______
View answer
22. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Iron replaces hydrogen from
water.
Red hot
3Fe + 4H2O Fe3O4 + 4H2 ↑
23. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Decomposition Reaction When a single compound
breaks up into two or many
simpler substances it is called
decomposition reaction.
Decomposition
Breaking of single compound into simpler
substances
24. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
When we heat lead nitrate it
becomes lead oxide with the
evolution of oxygen gas and
2Pb(NO3)2 Heat 2PbO + 4NO2↑ + O2 ↑ brown fumes of nitrogen
dioxide.
Brown fumes of
nitrogen dioxide
25. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Interactivity Watch this experiment and
Why does blue copper sulphate answer the question.
solution become white on heating?
View answer
26. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Blue copper sulphate pentahydrate undergoes
decomposition on heating to give white
anhydrous copper sulphate and water vapour.
CuSO4.5H2O CuSO4 + 5H2O
27. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Double Displacement Reaction
Two compounds react to form
different compounds by mutual
exchange of ions or atoms in a
double displacement reaction.
Double Displacement
Mutual exchange of ions in two different
compounds
28. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
When silver nitrate reacts
AgNO3 + KCl AgCl + KNO3 with potassium chloride, it
gives silver chloride and
potassium nitrate.
Silver nitrate solution Silver chloride solution
(Colourless) (Curdy white precipitate)
29. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Interactivity
Click the view answer button
to find out the product.
What happens when barium chloride is treated with
sodium sulphate?
View answer
30. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Barium chloride gives a white precipitate of
barium sulphate and sodium chloride.
BaCl2 + Na2SO4 BaSO4 ↓ + 2NaCl
31. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Neutralisation Reaction Neutralisation is also an
example of double
displacement reaction.
Acid reacts with base to
form salt and water.
Neutralisation
Acid + Base Salt + Water
32. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Equimolar mixture of sodium
hydroxide and hydrochloric
Neutralisation
acid result neutralisation
NaOH + HCl NaCl + H2O mixture, containing sodium
chloride salt and water .
Did you know?
When we add a few
drops of phenolphthalein
indicator in a
neutralisation mixture
with a slight excess of
alkali it gives pale pink
colour.
Pale pink colour of neutralisation
Colourless neturalisation mixture with slight excess of
mixture NaOH
33. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Interactivity
Click the view answer button
to find out the product.
Complete the reaction
Ca(OH)2 + H2SO4 ____ + ___
View answer
34. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Calcium hydroxide reacts with
sulphuric acid to form calcium
Ca(OH)2 + H2SO4 CaSO4↓ +2H2O sulphate and water.
Calcium hydroxide
Calcium sulphate
Sulphuric acid
35. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Oxidation - Reduction Combustion of gasoline,
burning of wood and
burning of food in our body
are examples of oxidation.
36. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
An oxidation reaction
occurs as a result of either
the addition of oxygen or
the removal of hydrogen. A
reduction reaction occurs
by either the removal of
Oxidation Reduction oxygen or the addition of
hydrogen.
Addition of oxygen Removal of oxygen
Removal of Addition of hydrogen
hydrogen
37. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Oxidation and reduction
occur simultaneously in a
reaction: hence it is called
redox reaction.
38. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Zinc oxide undergoes
reduction by losing oxygen to
Carbon become zinc, and carbon
undergoes oxidation by
gaining oxygen, to become
carbon monoxide.
Zinc oxide Calcium hydroxide
39. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Interactivity
Click the view answer button
to find out the product.
Identify oxidation and reduction.
H2S + Cl2 2HCl + S
View answer
40. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
H2S + Cl2 2HCl + S
H2S undergoes oxidation by the removal of
hydrogen. Cl2 undergoes reduction by the addition of
hydrogen.
41. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Thermal Dissociation A compound is dissociated
into simple compounds on
heating. Since this
dissociation takes place due
to heating it is called
‘thermal dissociation’.
Thermal = By heating
Dissociation = Splitting into simple compounds
42. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Hydrogen peroxide dissociates
on heating, to give water and
oxygen, in the presence of
In the presence of MnO2 manganese oxide.
Heat
2H2O2 2H2O + O2
MnO2
Hydrogen Water Oxygen
peroxide
43. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Interactivity
Click the view answer button
to find out the product.
What happens when ammonia is
heated in the presence of tungsten as
catalyst?
View answer
44. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Ammonia dissociates into
nitrogen and hydrogen in the
presence of tungsten.
Ammonia dissociates into nitrogen and
hydrogen in the presence of tungsten.
Heat
2NH3 N2 + 3H2
45. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Reversible and Irreversible Reactions You can compare reversible
and irreversible reactions as
S.No. Reversible reaction Irreversible reaction shown in the table.
1. The reaction can be The reaction can be started
started from either from the reactant side only.
side.
2. Forward and Only the forward reaction
backward reactions takes place.
are in equilibrium.
3. Represented by an Represented by an normal
equilibrium arrow arrow
4. The reaction is never The reaction proceeds to
complete. completion.
Next
46. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Thermal decomposition of
phosphorus pentachloride into
phosphorus trichloride and
chlorine is a good example of a
reversible reaction.
PCl5 PCl3 + Cl2
Phosphorus pentachloride Phosphorus trichloride
47. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Phosphorus pentachloride
dissociates into phosphorus
trichloride and chlorine in the
forward reaction
Forward reaction
PCl5 PCl3 + Cl2
Reactant Products
48. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Phosphorus trichloride and
chlorine combine with each
other to become phosphorus
pentachloride in the backward
reaction.
Backward reaction
PCl5 PCl3 + Cl2
Product Reactants
49. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Neutralisation between a strong
acid and strong base is an
irreversible reaction, with the
evolution of heat.
NaOH + HCl NaCl + H2O + 13.7 kcal
50. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Interactivity
Click the view answer button
to find out the product.
Match the type of reaction
1 ZnCO3 Heat ZnO + CO2 A Redox reaction
2 Mg + H2SO4 MgSO4 + H2 B Combination
reaction
3 2NaI + Cl2 2NaCl + I2 C Decomposition
reaction
4 4Na + O2 2Na2O D Single
displacement
reaction
View answer
51. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
1 ZnCO3 Heat ZnO + CO2 C Decomposition
reaction
2 Mg + H2SO4 MgSO4 + H2 D Single
displacement
reaction
3 2NaI + Cl2 2NaCl + I2 A Redox reaction
4 4Na + O2 2Na2O B Combination
reaction
52. CBSE - 10 Chemical Reactions and Equations
Chemistry Types of Chemical Reactions
Summary
Combination In this lesson you have learnt
different types of chemical
reactions such as combination ,
Reversible Decomposition decomposition, thermal
dissociation, redox,
& neutralisation, displacement,
Thermal double displacement ,
Irreversible dissociation reversible and irreversible
reactions.
Displacement
Redox
Double
Neutralisation
displacement
Types of Reaction