Zno crystal on heating acquires the formula zn1+xo. Give reasons
Answers
When ZNO is heated it looses oxygen and turns to yellow due to following chemical reaction :
ZNO---->Zn²⁺ + 1/2 O₂ + 2e ⁻
The excess of Zn2+ ions thus formed get trapped into the vacant interstitial site and the electrons in the neighbouring interstitial sites
Zno crystal on heating acquires the formula zn1+xo and turns yellow.On heating it shows metal excess intrinsic defect.
ZNO---->Zn²⁺ + 1/2 O₂ + 2e
On heating some of the oxide ions in crystal lattice leave their usual lattice site and creats anionic vacancy.Now these oxide ions looses electron to form molecular oxygen.These electrons occupy the anionic vacancy to maintain electro-neutal balance.These centres are considered as 'particle in 1 D box' and called f-centres. Due to this phenomenone zinc ions within the crystal get exess.