Question

A compound formed by two elements `M` and `N`. Element `N` forms ccp and atoms of `M` occupy `1//3rd` of tetrahedral voids. What is the formula of th compound?

Answer 1

Atoms on N from ccp, therefore, if the lattice points are n, then
No. of atoms of N=n
No. of oct voids =n
No. of td voids `=2n=2xx 1n//=2n//3`
`therefore` Formula of compound is `M:N`
2/3n:n
2n:3n
2:3
i.e, `M_(2)N_(3)`