Question

An element occurs in bcc structure with cell edge length of $250$ pm. If its density is $8.0$ g cm${}^{-3}$, its molar mass (in g/mol) will be :

• A. $37.5$
• B. $32.6$
• C. $45.2$
• D. none of the above

Answer 1

The correct option is A $37.5$

density $=\frac{zM}{N_a\times (a\times {10}^{-10}{)}^3}$
$8.0=\frac{2\times M}{6.023\times {10}^{23}\times (250\times {10}^{-10}{)}^3}$
$M=37.5\text{g/mol}$