Solutions CW 3
1. Determine the solubility of NH4Cl at 50°C in 100 g of H2O.
2. Calculate the mass of Ca(OH)2 (molar mass = 74.093 g/mol) present in 275
mL of 11.0 M solution.
3. What volume of 12.0 M solution should be used in order to prepare a 2.5 L
solution that is 1.5 M?
4. How much more KNO3 can be dissolved at 60°C than at 30°C?
5. Calculate the volume, in mL, of a 3.0 M solution containing 25 g of Li2S (molar
mass = 45.95 g/mol).
6. 30 g of KClO3 is added to 100 g of water at 80°C, is the solution saturated or
unsaturated?
7. While preparing a 350 mL 2.2 M solution you accidentally pour in 530 mL.
What is the concentration of the resulting solution?
8. Calculate the volume of a 4.0 M solution containing 0.25 moles of solute.
9. How many moles of KCl (molar mass = 74.5513 g/mol) are present in 1.25 L
of 5.0 M solution
10. What is the minimum temperature required to dissolve 40 g of KCl in 100 g
of water?
11. Determine the concentration of a 785 mL solution containing 294.2 g of KNO3
(molar mass = 101.1032 g/mol).
12. If 30 g of KClO3 is added to 100 g of water at 30°C how much will not
dissolve?
13. If 80 g of NaCl is added to 100 g of water at 70°C, is the solution saturated or
unsaturated?
Solutions CW 3 Answers
1. Determine the solubility of NH4Cl at 50°C in 100 g of H2O.
50 g
2. Calculate the mass of Ca(OH)2 (molar mass = 74.093 g/mol) present in 275
mL of 11.0 M solution.
11.0 = n / 0.275
n = 3.0 moles
3.0 (74.093) = 220 g
3. What volume of 12.0 M solution should be used in order to prepare a 2.5 L
solution that is 1.5 M?
(12.0) (V1) = (1.5) (2.5)
V1 = 0.31 L or 310 mL
4. How much more KNO3 can be dissolved at 60°C than at 30°C?
(102 – 45) = 57 g
5. Calculate the volume, in mL, of a 3.0 M solution containing 25 g of Li2S (molar
mass = 45.95 g/mol).
25 / 45.95 = 0.54 moles
3.0 = 0.54 / V
V = 0.18 L  180 mL
6. 30 g of KClO3 is added to 100 g of water at 80°C, is the solution saturated or
unsaturated?
Unsaturated (solubility = 40 g at 80°C)
7. While preparing a 350 mL 2.2 M solution you accidentally pour in 530 mL.
What is the concentration of the resulting solution?
(2.2) (350) = M2 (530)
M2 = 1.5 M
8. Calculate the volume of a 4.0 M solution containing 0.25 moles of solute.
4.0 = 0.25 / V
V = 0.063 L  63 mL
9. How many moles of KCl (molar mass = 74.5513 g/mol) are present in 1.25 L
of 5.0 M solution
5.0 = n / 1.25
n = 6.3 moles
10. What is the minimum temperature required to dissolve 40 g of KCl in 100 g
of water?
50°C
11. Determine the concentration of a 785 mL solution containing 294.2 g of KNO3
(molar mass = 101.1032 g/mol).
294.2 / 101.1032 = 2.910 moles
2.910 / 0.785 = 3.71 M
12. If 30 g of KClO3 is added to 100 g of water at 30°C how much will not
dissolve?
10 g will dissolve so 20 g will not dissolve
13. If 80 g of NaCl is added to 100 g of water at 70°C, is the solution saturated or
unsaturated?
Solubility is 38 g, so it is Saturated