Question

The density of solid argon (Ar = 40 g/mol) is 1.68 g/mL at 40 K. If the argon atom is assumed to be a sphere of radius = 1.50 × 10^–8 cm, what % of solid Ar is apparently empty space?

• A. 35.64
• B. 64.36
• C. 74%
• D. None of these

Answer 1

Answer: (B)

64.36

Answer 2

Vol. of all atoms in 1.68 gm

argon =$\frac{1.68}{40} \times N_{A} \times \frac{4}{3} \times \pi \times (1.5 \times 10^{–8})^{3}$ = 0.3564

vol. of solid argon = 1 cm³

% empty space = (1 – 0.3564) × 100 = 64.36