The heat of vaporization delta Hv of dichloromethane (Ch2CL2) is 28.0 kJ/mol . Calculate the change in entropy delta S when 473 g of dichloromethane boils at 39.8 degree.

16 J/K.mol

Explanation:

From the question,

ΔS = ΔH/T Equation 1

Where ΔH = Heat change, T = Temperature

But,

ΔH = n(Hv) Equation 2

Where n = number of  mole, Hv = heat of vaporization.

Given: Hv = 28.0 kJ/mol, n = 473/85 = 5.59 mole.

Substitute these values into equation 2

ΔH = 28/5.59

ΔH = 5.01 kJ.

Also: T = 273+39.8 = 312.8 J

Substitute into equation 1

ΔS = 5.01/312.8

ΔS = 0.016 kJ/K

ΔS = 16 J/K.mol