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

Answer: (A)

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