1 Kg of water is pumped to a height of 1 m, the enthalpy is changed by 5 J/Kg, and work done by the motor is 25 J/Kg, assuming a system is insulated what is the change in internal energy of water?
(a) 10 J
(b) 25 J
(c) 35 J
(d) 50 J
The question was asked during an internship interview.
Origin of the question is Application of the Energy Balance to Open Systems topic in chapter Application of Energy Balances in the Absence of Chemical Reactions and Energy Balances: How to Account for Chemical Reaction of Basic Chemical Engineering