Assuming the water vapour is an ideal gas, the internal energy change (Delta U) when 1 mole of water is vapourised at 1 bar pressure and 100^(@)C(given molar enthalpy of vapourisation of watyer at 1 bar and 373 K = 41 kJ mol^(-1) and R = 8.3 J mol^(-1)K^(-1)) will be

Assuming the water vapour is an ideal gas, the internal energy change

1.	Assuming the water vapour is an ideal gas, the internal energy change (Delta U) when 1 mole of water is vapourised at 1 bar pressure and 100^(@)C(given molar enthalpy of vapourisation of watyer at 1 bar and 373 K = 41 kJ mol^(-1) and R = 8.3 J mol^(-1)K^(-1)) will be
Answer» `3.7904 kJ"mol"^(-1)` `37.904 kJ"mol"^(-1)` `41.00 kJ"mol"^(-1)` `4.100 kJ"mol"^(-1)` Solution :`H_(2)O(l) to H_(2)O(g)` `DELTAG = 41 kJ mol^(-1)` `DELTAH = DeltaU + Deltan_(g)RT` `Deltan_(g) = 1` `41 = DeltaU + 1 xx 8.3 xx 10^(-3) xx 373` `41 = DeltaU + 3.096` `DeltaU = 41 - 3.096 = 37.904 kJ mol^(-1)`.