A substance AxBY crystallizes in a face centred cubic (fcc) lattice in which atoms 'A' occupy each corner of the cube and atoms 'B' occupy the centres of each face of the cube. Identify the correct composition of the substance AxBY :

Question

A substance AxBY crystallizes in a face centred cubic (fcc) lattice in which atoms 'A' occupy each corner of the cube and atoms 'B' occupy the centres of each face of the cube. Identify the correct composition of the substance AxBY : (A) AB3 (B) A4B3 (C) A3B (D) Composition cannot be specified

Tardigrade Admin · Accepted Answer

Effective number of corner atom (A) =8× (1/8)=1=X Effective number of face centred atom (B) =(1/2)× 6=3=Y Thus, composition of substance =AB3 .

Q. A substance $A_{x} B_{Y}$ crystallizes in a face centred cubic (fcc) lattice in which atoms $^{'} A^{'}$ occupy each corner of the cube and atoms $^{'} B^{'}$ occupy the centres of each face of the cube. Identify the correct composition of the substance $A_{x} B_{Y}$ :

$A B_{3}$

$A_{4} B_{3}$

$A_{3} B$

Composition cannot be specified

Effective number of corner atom $(A)$
$= 8 \times \frac{1}{8} = 1 = X$
Effective number of face centred atom $(B)$
$= \frac{1}{2} \times 6 = 3 = Y$
Thus, composition of substance $= A B_{3}$ .

Q. A substance Ax​BY​ crystallizes in a face centred cubic (fcc) lattice in which atoms ′A′ occupy each corner of the cube and atoms ′B′ occupy the centres of each face of the cube. Identify the correct composition of the substance Ax​BY​ :

AB3​

A4​B3​

A3​B