Suppose that approximately one-third of the octahedral holes in the fcc lattice of iron (Fe; r= 126 pm) is occupied by a carbon atom (C; r = 77 pm).Which of the following is its probable composition?

Question

Quizplus · Accepted Answer

In an fcc lattice, there are 4 atoms per unit cell and 4 octahedral holes. If one-third of the octahedral holes are occupied by carbon, then approximately 1 carbon atom is present per 3 iron atoms, leading to the composition Fe₃C.

Suppose That Approximately One-Third of the Octahedral Holes in the Fcc