Calculate the molecular masses of

1. H₂
2. O₂
3. Cl₂
4. CO₂
5. CH₄
6. C₂H₆
7. C₂H₄
8. NH₃
9. CH₃OH.

1. The molecular mass of H₂ = 2 x atoms atomic mass of H = 2 x 1u = 2u

2. The molecular mass of O₂ = 2 x atoms atomic mass of O = 2 x 16u = 32u

3. The molecular mass of Cl₂ = 2 x atoms atomic mass of Cl = 2 x 35.5u = 71u

4. The molecular mass of CO₂ = atomic mass of C + (2 x atomic mass of O) = 12 + (2 × 16)u = 12 + 32 = 44u

5. The molecular mass of CH₄ = atomic mass of C + (4 x atomic mass of H) = 12 + (4 x 1) = 16u

6. The molecular mass of C₂H₆ = (2 x atomic mass of C) + (6 x atomic mass of H) = (2 x 12) + (6 x 1) = 24 + 6 = 30u

7. The molecular mass of C₂H₄ = (2 x atomic mass of C) + (4 x atomic mass of H) = (2 x 12) + (4 x 1) = 24 + 4 = 28u

8. The molecular mass of NH₃ = atomic mass of N + (3 x atomic mass of H) = 14 + (3 x 1) = 17u

9. The molecular mass of CH₃OH = atomic mass of C + (3 x atomic mass of H) + atomic mass of O + atomic mass of H = [12 + (3 × 1) + 16 + 1] = (12 + 3 + 17) = 32u