Calculate the mass of bcc unit cell if metal has molar mass $56 \mathrm{~g} \mathrm{~mol}^{-1}$.
Calculate the mass of bcc unit cell if metal has molar mass $56 \mathrm{~g} \mathrm{~mol}^{-1}$.
$1.86 \times 10^{-22}$ gram
$9.3 \times 10^{-24}$ gram
$2.79 \times 10^{-24}$ gram
$3.72 \times 10^{-22}$ gram
Solution
$\begin{aligned} & \text { Mass of an atom }=\frac{56}{6.02 \times 10^{23}} \mathrm{~g} \\ & \text { Mass of unit cell }=\frac{2 \times 56}{6.02 \times 10^{23}} \\ & =18.6 \times 10^{-23} \\ & \text { or } 1.86 \times 10^{-22} \mathrm{~g}\end{aligned}$