Translate the following statements into chemical equations and then balance them.

(a) Hydrogen gas combines with nitrogen to form ammonia.

(b) Hydrogen sulphide gas burns in air to give water and sulfur dioxide.

(c) Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate  of barium sulphate.

(d) Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.

 

Answer

 

  • H 2 + N 2  →  NH 3

 

Name of the element

No. of atoms in Reactants

No. of atoms in Products

Hydrogen

2

3

Nitrogen

2

1

 

To balance Nitrogen,

Multiply NH 3 by 2

H 2 + N 2  →  2 NH 3

 

Name of the element

No. of atoms in Reactants

No. of atoms in Products

Hydrogen

2

6

Nitrogen

2

2

 

Now, to balance Hydrogen,

Multiply H 2 by 3

3 H 2 + N 2  →  2 NH 3

 

Name of the element

No. of atoms in Reactants

No. of atoms in Products

Hydrogen

6

6

Nitrogen

2

2

 

Now, all the elements are balanced and the balanced equation is

3 H 2 + N 2  →  2 NH 3

 

3 H 2 + N 2  →  2 NH 3



  • H 2 S + O 2  →  H 2 O + SO 2

 

Name of the element

No. of atoms in Reactants

No. of atoms in Products

Hydrogen

2

2

Sulphur

1

1

Oxygen

2

3

 

To balance Oxygen,

Multiply H 2 O   by 2

H 2 S + O 2  →  2 H 2 O + SO 2

 

Name of the element

No. of atoms in Reactants

No. of atoms in Products

Hydrogen

2

4

Sulphur

1

1

Oxygen

2

4

 

To balance Hydrogen,

Multiply H 2 S   by 2

2 H 2 S + O 2  →  2 H 2 O + SO 2

 

Name of the element

No. of atoms in Reactants

No. of atoms in Products

Hydrogen

4

4

Sulphur

2

1

Oxygen

2

4

 

To balance Sulphur,

Multiply SO 2   by 2

2 H 2 S + O 2   →  2 H 2 O + 2 SO 2

 

Name of the element

No. of atoms in Reactants

No. of atoms in Products

Hydrogen

4

4

Sulphur

2

2

Oxygen

2

6

 

To balance Oxygen,

Multiply O by 3

2 H 2 S + 3 O 2  →  2 H 2 O + 2 SO 2

 

Name of the element

No. of atoms in Reactants

No. of atoms in Products

Hydrogen

4

4

Sulphur

2

2

Oxygen

6

6

 

Now, all the elements are balanced and the balanced equation is

2 H 2 S + 3 O 2  →  2 H 2 O + 2 SO 2

 

2 H 2 S + 3 O 2  →  2 H 2 O + 2 SO 2




(c) BaCl 2 + Al 2 (SO 4 ) →  BaSO 4 + AlCl 3

 

Element Name

No of Atoms in Reactant

No of Atoms in Product

Barium

1

1

Chlorine

2

3

Aluminium

2

1

Sulphur

3

1

Oxygen

12

4

 

To balance Oxygen,

Multiply BaSO 4   by 3

BaCl 2 + Al 2 (SO 4 ) 3   →  3 BaSO 4 + AlCl 3

 

Element name

No. of atoms in reactants

No. of atoms in products

Barium

1

3

Chlorine

2

3

Aluminium

2

1

Sulphur

3

3

Oxygen

12

12

 

To balance Aluminium,

Multiply AlCl 3   by 2

BaCl 2 + Al 2 (SO 4 ) 3 →  3 BaSO 4 + 2 AlCl 3

 

Element name

No. of atoms in reactants

No. of atoms in product

Barium

1

3

Chlorine

2

6

Aluminium

2

2

Sulphur

3

3

Oxygen

12

12

 

To balance Barium and Chlorine,

Multiply BaCl 2   by 3

3 BaCl 2 + Al 2 (SO 4 ) 3   →  3 BaSO 4 + 2 AlCl 3

 

Name of the element

No. of atoms in Reactant

No. of atoms in Product

Barium

3

3

Chlorine

6

6

Aluminium

2

2

Sulphur

3

3

Oxygen

12

12

 

Now, all the elements are balanced and the balanced equation is

3 BaCl 2 + Al 2 (SO 4 ) 3   →  3 BaSO 4 + 2 AlCl 3

 

3 BaCl 2 + Al 2 (SO 4 ) →  3 BaSO 4 + 2 AlCl 3




(d) K + H 2 O → KOH + H 2

 

Name of the element

No. of atoms in Reactants

No. of atoms in Products

Potassium

1

1

Hydrogen

2

3

Oxygen

1

1

To balance Hydrogen,

Multiply KOH   by 2

K + H 2 O → 2 KOH + H 2

 

Name of the element

No. of atoms in Reactants

No. of atoms in Products

Potassium

1

2

Hydrogen

2

4

Oxygen

1

2

 

To balance Oxygen and Hydrogen,

Multiply H 2 O   by 2

K + 2 H 2 O → 2 KOH + H 2

 

Name of the element

No. of atoms in Reactants

No. of atoms in Products

Potassium

1

2

Hydrogen

4

4

Oxygen

2

2

 

To balance Potassium,

Multiply K   by 2

2 K + 2 H 2 O → 2 KOH + H 2

 

Name of the element

No. of atoms in Reactants

No. of atoms in Products

Potassium

2

2

Hydrogen

4

4

Oxygen

2

2

 

Now, all the elements are balanced and the balanced equation is

2 K + 2 H 2 O → 2 KOH + H 2

 

2 K + 2 H 2 O → 2 KOH + H 2

  1. Class 10
  2. Chapter 1 Class 10 - Chemical Reactions and Equations (Term 1)

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo