In a cubic crystal the cation M is at the 8 corners, cation N is at the body centre and the anion X^2- is at the centres of all 12 edges. The charge on N, given that M is +2, is

JEE Advanced levelSingle correct optionDifficulty 3 of 3ss141

In a cubic crystal the cation $M$ is at the 8 corners, cation $N$ is at the body centre and the anion $X X^{2 -}$ is at the centres of all 12 edges. The charge on $N$ , given that $M$ is $+ 2$ , is

M = 8 \times \frac{1}{8} = 1

N = 1

X = 12 \times \frac{1}{4} = 3

, so the formula is

MNX X_{3}

. Charge balance:

2 + x = 3 \times 2

, so

x = + 4