AP EAMCET201823 Apr 2018Evening ShiftChemistrySolid StateActual
A metal oxide crystallises in a hexagonal close-packed array of oxide ions with two out of every three octahedral holes occupied by metal ions. The formula of metal oxide is
Options
- AM O
- BM₃ O ₄
- CM₂ O ₅
- DM₂ O ₃
Correct answer
D. M₂ O ₃
Step-by-step solution
Unit cell of hcp structure =6 number of oxide ions per unit cell =6 number of octahedral voids =6 . Since, ferric ions occupy only two out of every three octahedral voids, number of octahedral holes occupied by ferric ions 2 3 6=4 stoichiometric ratio of metal and ion =4: 6=2: 3 . Hence, formula of metal oxide is M₂ O ₃ .