Question

Use the van der Waals equation of state to calculate the pressure of 2.70 mol of Cl2Cl2 at 451 K in a 4.80 L vessel.

Answer 1

Solution:

According to Vanderwaal equation, the pressure (P) is calculated as,

P = (nRT/V-nb) - (n^2 a/V^2)

The vanderwaal constants a and b for Cl2 are:

a = 6.49 L^2atm /mol^2

b= 0.0562 L/mol

n = 2.70 mol

T = 451 K

V = 4.80 L

Thus,

P = (2.70 mol x 0.0821 L atm K-1 mol-1 x 451 K) / (4.80L - 2.70 mol x 0.0562 L/mol) - ( 2.70 mol x 2.70 mol x 6.49 L2 atm/mol^2 / 4.80 L x 4.80 L)

P = (99.97317 / 4.648) atm - ( 1.996) atm

P = 21.509 atm - 1.996 atm = 19.51 atm