Question

The crystal with metal deficiency defect is

• A. $NaCl$
• B. $FeO$
• C. $KCI$
• D. $ZnO$

Answer 1

Answer: (B)

$FeO$

Answer 2

In FeO, as some Fe atoms may be present as ${Fe^{3+}}$ and for charge neutrality, ${3 \, Fe^{2+} = 2 \, Fe^{3+}}$, hence FeO would have metal deficiency defect.