Question

A solid has a structure in which W atoms are located at the corners of a cubic lattice, O atoms at the centres of edges and Na atom at the centre of the cube. The formula of the compound is

• A. $NaW{O}_2$
• B. $NaW{O}_3$
• C. $N{a}_{2}W{O}_3$
• D. $NaW{O}_4$

Answer 1

The correct option is B

$NaW{O}_3$

Number of W - atoms per unit cell $=\frac{1}{8}\times 8=1$
Number of O - atoms per unit cell $=\frac{1}{4}\times 12=3$
Number of Na - atoms per unit cell = 1 at the centre.
Hence, formula of the compound : $NaW{O}_3$