KVPY2017ChemistrySolid State
A mineral consists of a cubic close-packed structure formed by O ²⁻ ions where half the octahedral voids are occupied by Al ³⁺ and oneeighth of the tetrahedral voids are occupied by Mn ²⁺ . The chemical formula of the mineral is
Options
- AMn ₃ Al ₂ O ₆
- BMnAl ₂ O ₄
- CMnAl ₄ O ₇
- DMn ₂ Al ₂ O ₅
Correct answer
B. MnAl ₂ O ₄
Step-by-step solution
No of O ⁻² per unit cell =8 1 8 +6 1 2 =4 No of Al ⁺³ per unit cell =4 1 2 =2 No of Mn ⁺² per unit cell =8 1 8 =1 M n A l ₂ O ₄