Question

The unit length convenient on the atomic scale is known as an angstrom and is denoted by $\mathring{A}:(1\mathring{A}={10}^{-10}m)$. The size of a hydrogen atom is about 0.5 $\mathring{A}$. What is the total atomic volume in $m^3$ of a mole of hydrogen atoms?

Answer 1

Radius of hydrogen atom, r = 0.5 Å = 0.5 × 10^-10 m
Volume of hydrogen atom = (4/3) π r³
= (4/3) × (22/7) × (0.5 × 10^-10)³
= 0.524 × 10^-30 m³

1 mole of hydrogen contains 6.023 × 10²³ hydrogen atoms.
∴ Volume of 1 mole of hydrogen atom $=$ 6.023 × 10²³ × 0.524 × 10^–30
$=$ 3.16 × 10^–7 m³