Q6 / 90 · KVPY 2012 (SB/SX) · Chemistry
The inter-planar spacing between the ( 221$)$ planes of a cubic lattice of length $450 \mathrm{pm}$ is $-$
- A$50 \mathrm{pm}$
- Correct answerB$150 \mathrm{pm}$
- C$300 \mathrm{pm}$
- D$450 \mathrm{pm}$
Solution
$\begin{array}{l}
\mathrm{d}_{\mathrm{hkl}}=\frac{\mathrm{a}}{\sqrt{\mathrm{h}^{2}+\mathrm{k}^{2}+1^{2}}} \\
=\frac{450}{\sqrt{4+4+1}}=\frac{450}{\sqrt{9}}=150 \mathrm{pm}
\end{array}$
Hence, the correct answer is option: 'B'.