Question

Write the molecular formulae for the following compound-

Iron (III) sulfide

Answer 1

Molecular formula

• The number of atoms of each element in one molecule of a compound is expressed by the molecular formula.

Molecular formula for Iron (III) sulfide

• Write the constituent elements and their valencies as shown below.
• Then we must crossover the valencies of the combining atoms.

• Hence, the molecular formula of Iron (III) sulfide is ${\mathrm{Fe}}_2{\mathrm{S}}_3$.