Question

A compound is formed by two elements A and B. Atoms of element A forms the ccp lattice and those of element B occupies one third of the tetrahedral voids. The formula of the compound is:
[0.77 Mark]

• A. $A_3{B}_2$
• B. $A_2{B}_3$
• C. $A{B}_3$
• D. $A{B}_2$

Answer 1

The correct option is A $A_3{B}_2$

Let, atoms of element $A=N$
Then, atoms of element $B=\frac{1}{3}\times 2N$$(\text{No. of tetrahedral voids}=2\times \text{No. of atoms making the lattice)}=\frac{2}{3}N$
$\therefore$ Formula of the compounds is $A_N{B}_{\frac{2}{3}N}=A_3{B}_2$