Question

Identify the correct formula for the compound ferric sulphate.

• A. $\text{Fe}{\text{SO}}_4$
• B. ${\text{Fe}}_2\text{(}{SO}_4{)}_3$
• C. ${\text{Fe}}_3\text{(}{SO}_4{)}_3$
• D. ${\text{Fe}}_3\text{(}{SO}_4{)}_2$

Answer 1

The correct option is B ${\text{Fe}}_2\text{(}{SO}_4{)}_3$

We know the valency of sulphate ion is 2, and ferric ion is 3.

So, for Ferric sulphate:
$\begin{array}{ccc}Symbol:& Fe& S{O}_4\\ Valency:& 3& 2\end{array}$

The formula will be ${\text{Fe}}_2\text{(}{SO}_4{)}_3$.
Therefore, Option (C) is the correct answer.