Why does white ZnO_{(s)} become yellow upon h | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(D) On heating,$ZnO$ loses oxygen as follows:$ZnO_{(s)} \stackrel{\Delta}{\longrightarrow} Zn^{2+} + \frac{1}{2} O_{2} + 2e^{-}$The $Zn^{2+}$ ions for

Vedclass · Accepted Answer

All of the above.

Vedclass · Answer

(D) On heating,$ZnO$ loses oxygen as follows:$ZnO_{(s)} \stackrel{\Delta}{\longrightarrow} Zn^{2+} + \frac{1}{2} O_{2} + 2e^{-}$The $Zn^{2+}$ ions formed occupy interstitial sites,and the electrons occupy neighboring interstitial sites to maintain electrical neutrality.These trapped electrons in the interstitial sites absorb energy from visible light and get excited,which imparts a yellow color to the $ZnO$ crystal.

Why does white $ZnO_{(s)}$ become yellow upon heating?

Similar Questions

For $NaCl$,the number of Schottky pairs per $cm^3$ at room temperature is

Analysis shows that nickel oxide has the formula $Ni_{0.98}O_{1.00}$. What fractions of nickel exist as $Ni^{2+}$ and $Ni^{3+}$ ions?

It is observed that $Li_2O$ is soluble in $NiO$ in small amounts,where $Li^+$ ions occupy some of the cation sites. Which of the following conclusions can be drawn?

If $10^{-4} \, \text{mole} \%$ of $SrCl_2$ is added to $NaCl$,the concentration of cation vacancies created is...... $(N_A = 6.02 \times 10^{23} \, \text{mol}^{-1})$

Ionic solids,which have anionic vacancies due to metal excess defect,develop colour. Explain with the help of a suitable example.

Vedclass Test Series

Exam Paper Generator

Online Exam Module