Chemistry

Problem

\text{FeO}

crystallises in

\text{NaCl}

type lattice. The crystal is however non-stoichiometric as

\text{Fe}_{0.96}\text{O}

and deficient in iron. Some cation sites are vacant and some contain

\text{Fe}^{3+}

so that it becomes electrically neutral. The % of cation sites vacant are .....