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
= 34a.m.u
Therefore, the relative molecular mass of hydrogen sulphide is 34a.m.u
