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 2 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 ) 3 → 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 → 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
