Question

The size of a hydrogen atom is about $0.5 \mathring{A} .$ The total atomic volume of a mole of hydrogen atoms is

• A. $3 \times 10^{-7} m ^{3}$
• B. $3 \times 10^{-8} m ^{3}$
• C. $3 \times 10^{-9} m ^{3}$
• D. $3 \times 10^{-11} m ^{3}$

Answer 1

Answer: (A)

Volume of a hydrogen atom $=\frac{4}{3} \pi r^{3}$
$=\frac{4}{3} \times 3.14 \times\left(0.5 \times 10^{-10}\right)^{3}=\frac{1}{2} \times 10^{-30} m ^{3}$
Total volume of a mole of hydrogen atom
$=\left(6.023 \times 10^{23}\right) \times\left(\frac{1}{2} \times 10^{-30}\right)=3 \times 10^{-7} m ^{3}$