See image — AITS & Test Series Chemistry Question

💡 Solution & Explanation

Fe3O4 is an example of inverse spinel, in which one Fe+3 ion present at tetrahedral void and one Fe+3 as well as one Fe+2 ion present at octahedral voids per unit cell. 3 1 Fe  ion is present at tetrahedral voids.   3 5 2 3 2 Fe d e t    Total 5 unpaired electrons.