Question

When ZnO is heated it turns
yellow and returns back to original
white colour on cooling. What
could be the reason ?​

Answer 1

Answer:

because on heating zn get oxidised and due to this it change into yellow

Answer 2

Explanation:

In ZnO, Zn2+ ions occupy the interstitial sites and electrons are trapped in the interstitial sites for the neutralization. Crystals that shows such type of defects are generally colored. Zinc oxide is white in color but on heating it turns into yellow because on heating it loses oxygen reversibly at high temperature.