Question

Which of the following crystal will show metal excess defect due to extra cation?

Options

• \[\ce{AgCl}\]

• \[\ce{NaCl}\]

• \[\ce{FeO}\]

• \[\ce{ZnO}\]

Answer 1

\[\ce{ZnO}\]

Explanation:

\[\ce{ZnO}\] shows a metal excess defect due to extra cations. When heated, zinc oxide loses oxygen, leaving behind extra zinc ions \[\ce{(Zn^2+)}\] that occupy interstitial positions. The electrons released during this process balance the charge, resulting in a metal excess defect.