The solubility of a substance is 12 g per 100 g water at 20 degree , and is 18 g per 100 g water at 60 degree , what is the mass of the substance can be crystallized in a saturated solution that contain 200 g of water , if the solution cooled from 60 to 20 degree ?

Answer 1

At 60C 200 g H2O will hold
18 x 200/100 = 36g and that is a saturated solution.
At 20C it will hold 12 x 200/100 = 24.
Difference is 36-24 = ?g

Answer 2

12g