Iron(II) oxide crystal has a cubic structure and each edge of the unit cell is . If the density of t — Solid State Chemistry Question

💡 Solution & Explanation

Molar mass of FeO = $56 + 16 = 72 \text{ g/mol}$. Edge length $a = 0.493 \times 10^{-7} \text{ cm}$. Volume $a^3 \approx 119.8 \times 10^{-24} \text{ cm}^3$. Using $d = \frac{Z \times M}{N_A \times a^3} \implies 4.0 = \frac{Z \times 72}{6.022 \times 10^{23} \times 119.8 \times 10^{-24}}$. Solving for $Z \implies Z = \frac{4.0 \times 72.14}{72} \approx 4$. Therefore, correct answer is 4.