Question

Calculate the molecular masses of the following compounds:
(i) Hydrogen sulphide, H₂S
(ii) Carbon disulphide, CS₂
(Atomic masses: H = 1 u; S = 32 u; C = 12 u)

Answer 1

(i) The molecular mass of hydrogen sulphide,
$$\begin{gathered} =2\times \mathrm{H}+\mathrm{S} \\ =2\times 1+32 \\ =34\mathrm{u} \end{gathered}$$

(ii) The molecular mass of carbon disulphide,
$$\begin{gathered} =\mathrm{C}+2\times \mathrm{S} \\ =12+2\times 32 \\ =76\mathrm{u} \end{gathered}$$