Question

Calculate the relative molecular mass of H₂S.

• A. 34 a.m.u.
• B. 64 a.m.u.
• C. 18 a.m.u.
• D. 16 a.m.u.

Answer 1

The correct option is A

34 a.m.u.

Atomic mass of hydrogen = 1 a.m.u.
Atomic mass of Sulphur = 32 a.m.u.

Thus, the molecular mass of hydrogen sulphide, which contains two atoms of hydrogen and one atom of sulphur is = 2 × 1 + 1 × 32 = 34 a.m.u.