Calculate the molar mass of the following substances.
(a) Ethyne, `C_(2)H_(2)`
(b) Sulphur molecule, `S_(8)`
(c) Phosphorus molecule, `P_(4)` (Atomic mass of phosphorus = 31)
(d) Hydrochloric acid, HCl
(e) Nitric acid, `HNO_(3)`

Answer

(a) 26 g
(b) 256 g
(c ) 124 g
(d) 36.5 g
(e) 63 g

Explanation

Molar mass of ethyne, `C_(2)H_(2)` = 2 × 12 + 2 × 1 = 26g
Molar mass of sulphur molecule, `S_(8)` = 8 × 32 = 256g
Molar mass of phosphorus molecule, `P_(4)` = 4 × 31 = 124g
Molar mass of hydrochloric acid, HCl = 1 + 35.5 = 36.5g
Molar mass of nitric acid, `HNO_(3)` = 1 + 14 + 3 × 16 = 63g