Question

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

Answer 1

x occupies CCP lattice
coordination number of CCP is 4=x

y occupies 2/3 of tetrahedral voids
number of tetrahedral voids is equal to the co or donation number
thus (2/3)*4= 8/3=y

simplifying x and y to their simplest ratio we get
x/y = 3/2

thus formula is x(3) y(2)

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 ${A4B3}$.