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MHT CET · Chemistry · Solid State

Find the void volume of fcc unit cell in \(\mathrm{cm}^3\) if the volume of fcc unit cell \(1.25 \times 10^{-22} \mathrm{~cm}^3\).

  1. A \(3.25 \times 10^{-23}\)
  2. B \(2.16 \times 10^{-23}\)
  3. C \(1.34 \times 10^{-23}\)
  4. D \(4.20 \times 10^{-23}\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(3.25 \times 10^{-23}\)

Step-by-step Solution

Detailed explanation

For fcc unit cell, packing efficiency \(=74 \%\)
\(\therefore \quad\) Percentage of unoccupied space (void volume)
\(\begin{aligned}
& =100-74=26 \% \\
& =1.25 \times 10^{-22} \mathrm{~cm}^3 \times \frac{26}{100} \\
& =3.25 \times 10^{-23} \mathrm{~cm}^3
\end{aligned}\)