Question

The heat of vaporization

ΔHv

of acetone

OCCH32

is

32.0

/kJmol

. Calculate the change in entropy

ΔS

when

273.g

of acetone boils at

56.5°C

.

Be sure your answer contains a unit symbol and the correct number of significant digits.

Answer 1

Solution :-

Delta H v = 32.0 kJ/ mol *1000 J / 1 kJ = 32000 J/mol

Mass of acetone = 273 g

Boiling point = 56.5 C +273 = 329.5 K

Lets calculate the heat needed to boil 273 g acetone

(273 g acetone * 32000 J per mol / 58.08 g ) = 150413 J

Now lets calculate the entropy change

Delta S = Delta Hv / T

             = 150413 J / 329.5 K

             = 456.5 J/K

So the entropy change for the process is 456.5 J/K