Question

Write the formulae for the following.
Iron(II) sulphide

Answer 1

• A chemical formula is a representation of a substance's molecular composition in terms of the symbols for the elements that make up the molecule.
• Iron(II) sulphide is a compound containing Iron as cation and Sulphur as anion with symbols and valencies $\mathrm{Fe}\mathrm{and}\mathrm{S}-+2\mathrm{and}-2.$
• By the criss-cross method, $$\begin{gathered} \mathrm{Fe}\mathrm{S} \\ +2-2 \\ \overline{\mathrm{FeS}} \end{gathered}$$.
• The chemical formula of Iron(II) sulphide is $\mathrm{FeS}$.