Q51 / 200 · NEET 2005 · Chemistry
Copper has face centered cubic (fcc) lattice with interatomic spacing equal to $2.54 Å$. The value of lattice constant for this lattice is:
- A$2.54 Å$
- Correct answerB$3.59 Å$
- C$1.27 Å$
- D$5.08 Å$
Solution
Given $2 \pi=2.54 Å$
$$
\Rightarrow \quad r=\frac{2.54}{2}=1.27 Å
$$
For fcc lattice:
$$
\begin{aligned}
r & =\frac{a}{2 \sqrt{2}} \\
a & =r 2 \sqrt{2} \\
& =1.27 \times 2 \times 1.44 \\
& =3.59 \mathrm{~A}^{\circ}
\end{aligned}
$$
Hence, the correct answer is option: 'B'.