Question

What is the formula of the compound in which the element y forms ccp lattice and atoms of x occupies 2/3rd of the tetrahedral voids?

Answer 1

Total no of octahedral voids in ccp=8 (it will present in each of the middele of the sides of the cube)

1/4 of the octahedral voids will contribute in one unit cell

So efactive voids in a unit cell=2

X is 2/3 of total efactive void

So effactive no of atom of X is 2*2/4

Effactive no atom of Y 4

Formula of compouse X4/3Y4=XY3

Answer 2

$\huge\boxed{\underline{\mathcal{\red{A}\green{N}\pink{S}\orange{W}\blue{E}\purple{R}}}}$

• ❤.. The number of tetralhedral voids formed is equal to twice the number of atoms of element B and only 2/3rd of these are occupied by the atoms of element A.
• ❤..Hence the ratio of the number of atoms of A and B is ${2×(2/3):1 or 4:3}$ and the formula of the compound is ${A4B3}$.