In corrundum, oxide ions are arranged in hexagonal close packing and aluminium ions occupy two-third of the octahedral voids. What is the formula fo corrundum ?

In corrundum, oxide ions are arranged in hexagonal close packing and a

1.	In corrundum, oxide ions are arranged in hexagonal close packing and aluminium ions occupy two-third of the octahedral voids. What is the formula fo corrundum ?
Answer» SOLUTION : SUPPOSE oxideions = n . Then octahedral voids = n Hence,` Al^(3+) " ions"= 2/3 xx n = (2n)/3` RATIO` Al^(3+): O^(2-)= (2n)/ 3 : n = 2: 3`FORMULA is ` Al_(2)O_(3)` \