Question

Silver crystallizes in face-centered cubic structure. The edge length of the unit cell is found to be 408.7 pm. Calculate the density of silver. ($Ag=108g{mol}^{-1}$)

Answer 1

Theoretical density of a crystal, $\rho =\frac{nM}{N_o{a}^3}g/c{m}^3$

For FCC, $n=4;M=100g/mol;a=408.7\times {10}^{-10}cm$

$\Rightarrow \rho =\frac{4\times 108}{6.022\times {10}^{23}\times (408.7{)}^3\times {10}^{-30}}=10.5g/c{m}^3$