Question

The type of holes occupied by $A{l}^{3+}$ ions is__________.

• A. tetrahedral
• B. octahedral
• C. both A and B
• D. none of the above

Answer 1

The correct option is B octahedral

As $O^{2-}$ ions forms ccp, spinel has $4$ negative ions in its structure. So, total positive charge should be $8$.
It has one $M{g}^{+2}$ ion occupying one-eight of the tetrahedral holes and $2$ $A{l}^{+3}$ ions occupying one-half of the octahedral holes. So, the compound is $MgA{l}_2{O}_4$.