Question

Give the chemical formulae for the following compounds and compute the ratio by mass of the combining elements in each one of them.

(a) Ammonia (b) Carbon monoxide

(c) Hydrogen chloride (d) Aluminium fluoride

(e) Magnesium sulphide.

Answer 1

(a)Chemical formula of Ammonia =${\mathrm{NH}}_3$

Ratio by mass =$$\begin{gathered} 1N:3H \\ 14:3 \\ =14:3 \end{gathered}$$

b) Chemical formula of Carbon monoxide= $\mathrm{CO}$

Ratio by mass =$$\begin{gathered} \mathrm{C}:\mathrm{O} \\ 12:16 \\ =3:4 \end{gathered}$$

(C)Chemical formula of Hydrogen chloride=$\mathrm{HCl}$

Ratio by mass=$$\begin{gathered} \mathrm{H}:\mathrm{Cl} \\ 1:35.5 \end{gathered}$$

D)Chemical formula of Aluminium fluoride=${\mathrm{AlF}}_3$

Ratio by mass =$$\begin{gathered} Al:3F \\ 26:3\times 18 \\ 26:54 \end{gathered}$$

E)Chemical formula of Magnesium sulphide-$\mathrm{MgS}$

Ratio by mass=$$\begin{gathered} \mathrm{Mg}:\mathrm{S} \\ 24:32 \\ 3:4 \end{gathered}$$