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 Å , what % of solid Ar is apparently empty space?

• A. 35.64
• B. 64.36
• C. 74
• D. none of these

Answer 1

The correct option is B 64.36

Volume of all atoms in 1.68 g of Ar =
$\frac{1.68}{40}$ x6 x${10}^{23}$ x4/3 x22/7 x($1.{50}^3$ x${10}^{-24}$) = 0.3564
Vol. of solid Ar = 1 ${\mathrm{cm}}^3$
% Vol. of empty space
= (1 - 0.3564) x100 = 64.36