Question

The weight of a molecule of the compound $C_{60}{H}_{122}$ is

• A. $1.4\times {10}^{-21}g$
• B. $1.09\times {10}^{-21}g$
• C. $5.025\times {10}^{23}g$
• D. $16.023\times {10}^{23}g$

Answer 1

The correct option is A $1.4\times {10}^{-21}g$

Molecular weight of $C_{60}{H}_{122}=12\times 60+122\times 1=720+122=842$
$\because 6\times {10}^{23}$ molecule $C_{60}{H}_{122}$ has mass = 842gm
$\therefore$ 1 molecule $C_{60}{H}_{122}$ has mass $\frac{842}{6\times {10}^{23}}$
$=140.333\times {10}^{-23}gm=1.4\times {10}^{-21}gm$.