Question

A solid has a ccp arrangement of o2- ions. All of the tetrahedral voids are occupied by na+ ions. Find the molecular formula?

Answer 1

Given:

Ccp arrangement is formed by O²⁻ ions.

All the tetrahedral voids are occupied by Na⁺ ions.

To Find:

The molecular formula of the compound.

Calculation:

- Let the no of atoms in ccp arrangement be n.

⇒ The no of tetrahedral voids = 2n

- So, the no of O²⁻ ions in the lattice is n and the no of Na⁺ ions is 2n.

- The ratio of atoms :

Na⁺ : O²⁻ = 2n : n = 2 : 1

- So, the molecular formula of the given compound becomes Na2O.