Question

A compound forms hexagonal close-packed structure. What is the total number of voids in 0.5 mol of it? How many of these are tetrahedral voids ?

Answer 1

No. of atoms in the close packing =0.5 mol =`0.5 xx 6.022xx10^23 =3.011xx10^23`
No. of octahedral voids= No. of atoms in the packing =`3.011xx10^23`
No. of tetrahedral voids= 2 x No. of atoms in the packing =`2xx3.011xx10^23 =6.022xx10^23`
Total no. of voids =`3.011xx10+6.022xx10^23=9.033xx10^23`