The unit cell of is FCC with . If density , the value of '' is — Solid State Chemistry Question

💡 Solution & Explanation

Edge length $a = 1.26 \times 10^{-7} \text{ cm}$. Volume $V = 2 \times 10^{-21} \text{ cm}^3$. Molar mass $M = \frac{d \times N_A \times V}{Z} = \frac{2.14 \times 6.0 \times 10^{23} \times 2 \times 10^{-21}}{4} = 642 \text{ g/mol}$. The formula mass is $207 + 27 + 2(96) + 18x = 426 + 18x$. Equating the two: $426 + 18x = 642 \implies 18x = 216 \implies x = 12$. Therefore, correct answer is 0012.