Question

Zinc oxide loses oxygen on heating according to the reaction,
$ ZnO \stackrel{\text { heat }}{\longrightarrow} Zn ^{2}+\frac{1}{3} O _{2}+2 e^{-} $
It becomes yellow on heating because

• A. $Zn^{2+}$ ions and electrons move to interstitial sites and $F$-centres are created
• B. oxygen and electrons move out of the crystal and ions become yellow
• C. $Zn^{2+}$ again combine with oxygen to give yellow oxide
• D. $Zn^{2+}$ are replaced by oxygen

Answer 1

Answer: (A)

Correct answer is (a) $Zn^{2+}$ ions and electrons move to interstitial sites and $F$-centres are created