Question

Metallic copper crystallises in bcc lattice. The length of the cubic unit cell is $362$ pm. The density (in g cm${}^{-3}$) of crystalline copper is:

• A. $2.78$
• B. $3.51$
• C. $4.45$
• D. none of the above

Answer 1

Answer: (C)

$4.45$

For a BCC lattice, $z=2$
density = $\frac{zM}{N_a\times (a\times {10}^{-10}{)}^3}$
density = $\frac{2\times 65}{6\times {10}^{23}\times (362\times {10}^{-10}{)}^3}$
density = $4.45{\text{gcm}}^{-3}$