Question

An element $\mathrm{Z}$ has a valency of $4$. Write the formula for its nitrate.

Answer 1

It is given that the valency of an element $\mathrm{Z}$ is $4$, the molecular formula for its nitrate will be :

$$\begin{gathered} \mathrm{Symbol}\mathrm{Z}{\mathrm{NO}}_3 \\ \searrow \swarrow \\ \mathrm{Valency}4-1 \end{gathered}$$

As the valency of nitrate ion is $-1$, by applying the criss-cross method the molecular formula of the compound is $\mathrm{Z}{\left({\mathrm{NO}}_3\right)}_4$.