Practice Assignment 2.6 – Solubility Curve Graphs
1. Use a solubility curve to determine the solubility of the following compounds at the
temperatures given.
Compound
Temperature 0C
ANSWERS
NH3
10
70g/100mL
Ce2(SO4)3
50
5g/100mL
KCl
90
53g/100mL
2. For each of the following solutions, classify the solution as unsaturated, saturated, or
supersaturated.
Temperature 0C
Compound
NH3
NH4Cl
NaNO3
90
80
30
Mass of Solute in
100mL of Water
10
70
80
ANSWERS
Saturated
Supersaturated
Unsaturated
3. What is the solubility of ammonium chloride, NH4Cl, at 100°C?
Express this both as g /100mL of water and as mol/L of water
75g/100mL
13M
4. What mass of potassium chlorate, KClO3 could be dissolved in 100mL of water at 70°C?
33g/100mL
5. A saturated solution of potassium chloride at 80.0 oC is cooled to 40.0 oC. Explain the difference in the
mass at the bottom of each solution assuming there is 100 g of water.
10.g/100mL or 1.0*101g/100mL
6. Use a Table of Solubility of Common Compounds to predict whether or not the following compounds
will be soluble in water at 25°C.
Mg(NO3)2
CaCl2
Al2S3
(NH4)3PO4
SrCO3
BaSO4
Mg(CH3COO)2
SrI2
Soluble
Soluble
Low sol.
Soluble
Low sol.
Low sol.
Soluble
soluble
CaSO4
K2SO4
Ba(OH)2
Mg(OH)2
BeS
CuCl2
CuCl
H2CO3
Low sol.
Soluble
sol.
Low sol.
Soluble
Soluble
Low sol.
soluble
Cu2+ and Cu+ are different
ions and behave differently.
Only Cu+ has low solubility
with Cl-