Question

Potassium fluoride has a solubility of 92 g of KF in 100. g of H₂0 at 18 °C. Determine if

each of the following mixtures forms an unsaturated or saturated solution at 18 C:

a. adding 24 g of KF to 25 g of H₂O


b. adding 47 g of KF to 50. g of H₂O


c. adding 127 g of KF to 150. g of H₂O

Answer 1

a) In 25 grams of water, the solubility is 92/4 = 23 grams, so adding 24 grams will produce a supersaturated solution.

b) In 50 grams of water, the solubility is 92/2 = 46 grams, so adding 47 grams will produce a supersaturated solution.

c) In 150 grams of water, the solubility is 92(1.5) = 138 grams, so adding 127 grams will produce an unsaturated solution.