The solubility of KCL is water is 30g/100g of water at 20 degrees centigrade. A heated solution containing 60g of KCl in 140g of water is cooled to 20 degrees C. How many grams should precipitate out of solution?

Answer 1

Solubility is 30g/100g H2O at 20C; therefore, how much will 140 g hold?
That's 30 x (140/100) = ?
Subtract from 60 to find the amount that comes out of solution.