What is Delta S for the vaprization of trimethylamine?

Question

The normal boiling point of trimethylamine is 3 C and DeltaHvap is 22 kJ mol-1.

a) 66 J K-1 mol-1
b) 7.3 J K-1 mol-1
c) 6.1 J K-1 mol-1
d) 0 J K-1 mol-1
e) 80 J K-1 mol-1

Answer 1

OK...To answer this, you have to recognize that the free energy change at the boiling point is zero. So, beginning with DG (D=Delta), you have:

DG=DH-TDS=0

So, DS=DH/T

where T is the boiling point is Kelvin. If you substitute the values for DH and T, you can calculate the entropy change for the vaporization of trimethylamine.