Question

Calculate the molecular masses of the following compounds :
(a) Methanol, CH₃OH
(b) Ethanol, C₂H₅OH

Answer 1

(a) Given:
Atomic mass of C = 12 u
Atomic mass of O = 16 u
Atomic mass of H = 1 u
Therefore, molecular mass of CH₃OH can be calculated as follows:
(1 ×12) + (4 × 1) + (1 × 16) = 32
Hence, molecular mass of methanol is 32 u.

(b) Given:
Atomic mass of C = 12 u
Atomic mass of O = 16 u
Atomic mass of H = 1 u
Therefore, molecular mass of C₂H₅OH can be calculated as follows:
(2 × 12) + (6 × 1) + (1 ×16) = 46
Hence, molecular mass of ethanol is 46 u.