Question

Atoms of element X from hcp lattice and thos
elementy from occupy
3rd of the telrahedra
viods. Determine the formula of the compoun
formed by the elements X and Y ? (CTAT X
2
3​

Answer 1

Answer:

Y occupies CCP lattice hence the effective number of Y = 4 ( effective no of atoms in CCP is 4)

X occupies 2/3 of tetrahedral voids . Number of tetrahedral voids generated in any unit cell is = 2Z ( twice of an effective number of atoms in unit cell )

= 2×4 = 8

Since X occupies 2/3 of tetrahedral voids , so Effective number of X =

3

2

×8=

3

16

So X=

3

16

& Y=4 ,

Hence simplest formula is X

4

Y

3