Question

Using this table determine the van der Waal radius for Ar. Then use this radius to determine the fraction of volume occupied by 1 mol of argon at 25C and 1 atm.

Table 17.2 Lennard-Jones Parameters for Atoms and Molecules Particle e/kJ mol-1 o/Å 0.997 1.77 0.307 0.765 0.943 3.40 4.10 2.93 3.92 3.65 4.33 3.82 1.65 1.23 2.02 C6H6 8.60

Answer 1

The minimum van der Waals radius (r) can be calculated as follows.

r = $\sigma$/2

= (3.4/2) A^o

= 1.7 A^o

Volume = 4/3 $\pi$r³ = 4/3 $\pi$(1.7*10^-8 cm)³ = 20.5795*10^-24 cm³ = 2.06*10^-27 L (Note: 10³ cm³ = 1 L)