Question

Solution-1 containing 10% nitric acid and 20% acetic acid at the rate F combines with Solution-2 containing 20% nitric acid and 10% acetic acid at the rate D, the product formed contains 30% nitric acid and 20% acetic acid at the rate P, how many independent equations containing F, D, and P are possible?

(a) 1

(b) 2

(c) 3

(d) 4

This question was addressed to me in a national level competition.

This question is from Problem Solving Strategy topic in section A General Strategy for Solving Material Balance Problems and Solving Material Balance Problems for Single Units of Basic Chemical Engineering

Answer 1

Correct option is (c) 3

Easy explanation: The equations of material balance are: 0.1F + 0.2D = 0.3P, 0.2F + 0.1D = 0.2P, and F + D = P.