i. Molecular mass of H_{2}O = (2 × Average atomic mass of H) + (1 × Average atomic mass of O)

= (2 × 1.0u) + (1 × 16.0 u)

= 18 u

ii. Molecular mass of C_{6}H_{5}Cl = (6 × Average atomic mass of C) + (5 × Average atomic mass of H) + (1 × Average atomic mass of Cl)

= (6 × 12.0 u) + (5 × 1.0 u) + (1 × 35.5 u)

= 112.5 u

iii. Molecular mass of H_{2}SO_{4} = (2 × Average atomic mass of H) + (1 × Average atomic mass of S) + (4 × Average atomic mass of O)

= (2 × 1.0 u) + (1 × 32.0 u) + (1 × 16.0 u)

= 98 u

∴ i. The molecular mass of H_{2}O = 18 u

ii. The molecular mass of C_{6}H_{5}Cl = 112.5 u

iii. The molecular mass of H_{2}SO_{4} = 98 u