Question

What is the enthalpy of a mixture having 20% of A with enthalpy 20 J, 30% of B with enthalpy 40 J, and 50% of C with enthalpy 20 J?

(a) 26 J

(b) 29 J

(c) 31 J

(d) 34 J

The question was asked in an internship interview.

Query is from Heat of Solution, Dissolution and Mixing in chapter Energy Balances that Include the Effects of Chemical Reaction, Ideal Processes, Efficiency and the Mechanical Energy Balance and Heats of Solution and Mixing of Basic Chemical Engineering

Answer 1

Right option is (a) 26 J

For explanation I would say: Heat capacity of mixture = 0.2*20 + 0.3*40 + 0.5*20 = 26 J.