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 $C_{60}H_{122} =12\times60+122\times1= 720+ 122 = 842$
$\therefore 6 \times 10^{23}$ molecule $C_{60} H_{122}$ has mass $= 842 g$
$\therefore 1$ molecule $C_{60}H_{122}$ has mass $\frac{842}{6\times10^{23}}$
$= 140.333 \times 10^{-23} g$
$= 1.4 \times 10^{-21}g$