Question

assuming the water vapour to be a perfect gas , find the internal energy when 1 mole of water at 100 degree Celsius and 1 bar pressure is converted to ice 0 degree Celsius given the enthalpy of fusion of ice : 6.0 kj mol-1 .heat capacity of water :4.2 j/g degree Celsius.
​

Answer 1

Answer:

i) The reaction is: H

2

O

(l)

→H

2

O

(g)

We know that,

ΔH=ΔU+Δn

g

RT⟹ΔU=ΔH−Δn

g

RT

So on substituting the given values we get,

ΔU=41kJmol

−1

−

1000

8.3×373

⟹ΔU=37.904 kJ.mol

−1