Question

Ratio of change in internal energy of a substance from 15^oC to T and from T to 10^oC is – 2, what is T?

(a) 5^oC

(b) 15^oC

(c) 20^oC

(d) 30^oC

The question was asked at a job interview.

Question is taken from Internal Energy and Energy Conversion Concept topic in chapter Introduction to Energy Balances for Processes without Reaction and Calculation of Enthalpy Changes of Basic Chemical Engineering

Answer 1

Right answer is (a) 5^oC

The explanation is: – 2 = (T – 15)/(10 – T), => T = 5^oC.