Question

The chemical formula for ferrous sulphate heptahydrate is _____

Answer 1

Chemical formula

• A chemical formula identifies each constituent element by its chemical symbol and indicates the proportionate number of atoms of each element.

The chemical formula for ferrous sulfate as:

• The chemical symbol of ferrous ion is ${\mathrm{Fe}}^{+2}$
• The chemical symbol of sulfate ion is ${\left({\mathrm{SO}}_4\right)}^{-2}$
• Both ions combine together in a way such that

$$\begin{gathered} {\mathrm{Fe}}^{+2}{\left({\mathrm{SO}}_4\right)}^{-2} \\ 22(\mathrm{valency}\mathrm{is}\mathrm{cross}\mathrm{multiplied}\mathrm{to}\mathrm{get}\mathrm{the}\mathrm{compound}) \\ {\mathrm{Fe}}_2({\mathrm{SO}}_4{)}_2(\mathrm{simplifying}\mathrm{the}\mathrm{ratio}\mathrm{of}\mathrm{ions}) \\ {\mathrm{FeSO}}_4 \end{gathered}$$

• The hydrate molecule of ferrous sulfate is ferrous sulfate heptahydrate. it contains 7 molecules of water of crystallization, hence the formula becomes:

${\mathrm{FeSO}}_4.7{\mathrm{H}}_2\mathrm{O}$

Conclusion: The chemical formula for ferrous sulfate heptahydrate is${\mathrm{FeSO}}_4.7{\mathrm{H}}_2\mathrm{O}$