The internal energy change (in J) when of water undergoes complete evaporation at is
( Given :for water at,
Step 1: Given data:
Enthalpy of vaporization at is =
Universal gas constant value
Step 2: Formula used:
The internal energy can be calculated as
where, is internal energy of vaporization, no of moles, is enthalpy of vaporization. and temperature.
Step 3: Calculating the values of internal energy:
No of moles in 90 grams of water,
Enthalpy of vaporization in Joule
Therefore the internal energy change (in ) when of water undergoes complete evaporation at is.