1. Tardigrade
  2. Question
  3. Chemistry
  4. Percentage of free space in a body centred cubic unit cell is :

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. Percentage of free space in a body centred cubic unit cell is :

The Solid State

Solution:

Packing efficiency $=$

$\frac{\text { Volume occupied by two atoms in unit cell }}{\text { Volume of the unit cell }} \times 100$

For bcc, packing efficiency $=$

$\frac{2 \times \frac{4}{3} \times \pi r^{3}}{\left(\frac{4 r}{\sqrt{3}}\right)^{3}} \times 100=\frac{\sqrt{3} \pi}{8} \times 100=68 \%$

$\therefore $ Volume occupied $=68 \%$ and volume vacant $=$ $100-68=32 \%$