Chemistry - Solid State Question with Solution | TestHub

For a body-centered cubic (bcc) unit cell, the packing efficiency is $68\%$.

The percentage of empty space (void volume) in the unit cell is $100\%-68\%=32\%$.

Given the total volume of the unit cell is $V=1.5\times 10^{-22}{\mathrm{cm}}^3$.

Void volume = $32\%$ of $V=\frac{32}{100}\times 1.5\times 10^{-22}{\mathrm{cm}}^3$.

Void volume = $0.32\times 1.5\times 10^{-22}{\mathrm{cm}}^3=0.48\times 10^{-22}{\mathrm{cm}}^3=4.8\times 10^{-23}{\mathrm{cm}}^3$.

Answer: $4.8\times 10^{-23}$