Question

400 g of CaSO4 is dissolved with 500 g of H2O, if 226 g of CaSO4.5H2O crystallizes out, then what is the percentage of CaSO4 in the remaining solution?

(a) 39.16%

(b) 51.54%

(c) 62.28%

(d) 75.67%

I have been asked this question by my college director while I was bunking the class.

I'm obligated to ask this question of Solving Material Balance Problems for Single Units topic in division A General Strategy for Solving Material Balance Problems and Solving Material Balance Problems for Single Units of Basic Chemical Engineering

Answer 1

Correct choice is (a) 39.16%

The explanation: Moles of crystal = 226/226 = 1, => the crystal has 136 g of CaSO4 and 90 g of water, => Remaining solution has 264 g of CaSO4 and 410 g of H2O, => Percentage of CaSO4 in remaining solution = 264/(264 + 410) *100 = 39.16%.