Question

2 Kg of steam is enclosed in a container with internal energy = 5 J/Kg, then 5 J of heat is supplied to the system, what is the final internal energy?

(a) 7.5 J/ Kg

(b) 15 J/Kg

(c) 22.5 J/Kg

(d) 30 J/Kg

This question was posed to me by my school principal while I was bunking the class.

This interesting question is from Energy Balances for Closed, Unsteady-State Systems in section Introduction to Energy Balances for Processes without Reaction and Calculation of Enthalpy Changes of Basic Chemical Engineering

Answer 1

Right option is (a) 7.5 J/ Kg

Explanation: 5 = 2(U – 5), => U = 7.5 J/Kg.