The mole fraction of Schottky defects in a NaCl crystal at 1000 K is — Solid State Chemistry Question

💡 Solution & Explanation

Mole fraction $x = N/N_o = e^{-E/2RT}$. $E = 46000 \text{ cal/mol}$, $2RT = 2 \times 2 \times 1000 = 4000$. $E/2RT = 11.5$. $x = e^{-11.5}$. Taking ln, $\ln x = -11.5 \implies 2.3 \log x = -11.5 \implies \log x = -5 \implies x = 10^{-5}$. Therefore, correct answer is A.