Practice Problems
Chapter 16 Solutions
(1) Circle the letter of the best procedure for
making a 0.50-molar (0.50M) solution in a 1.0-L volumetric flask.
a. Add distilled water exactly to the 1.0-L mark, add 0.50 mol of solute, and
then agitate to dissolve the solute.
b. Place 0.50 mol of solute in the flask, add distilled water to the 1.0-L mark,
and then agitate to dissolve the solute.
c. Combine 0.50 mol of water with 0.50 mol of solute in the flask, and then
agitate to dissolve the solute.
d. Fill the flask with distilled water until it is about half full, add 0.50 mol
of solute, agitate to dissolve the solute, and then carefully fill the flask with
distilled water to the 1.0-L mark.
(3) Calculate the molarity of each solution.
a. 10 mol KCl in 750 mL of solution 13.3 M
b. .008 mol MgCl2 in 1.5 L of solution 0.0053 M
(4)How many milliliters of 0.500M CaCl2 solution would you need to dilute to make 100.0
mL of 0.100M CaCl2? 20 ml
(5)Calculate the grams of solute in each solution.
a. 8.0 L of 0.50M NaCl 234 g NaCl
b. 20.0 × 102 mL of 2.0M KNO3 404 g KNO3
c. 250 mL of 0.10M CaCl2 2.78 g CaCl2
(6)Calculate the moles of solute required to make the following solutions.
a. 3000 liter of saline solution (0.90M NaCl ) 2,700 mol
b. 200 ml of 3.0M MgCl2 0.6 mole
(7)What is the concentration (M) of the following solutions?
a. 12 mL of 10 M ethanol (C2H5OH) is diluted to a volume of 2000 mL with water.
0.06 M
b. 80 mL of 6 M isopropyl alcohol (C3H7OH) is diluted with water to a total volume
of 270 mL. 1.78 M
(8)Calculate the molarity of a solution containing 400 g CuSO4 in 4.00 L of solution. 0.626 M
(9)How many moles of KNO3 are present in 50.0 mL of 0.20M KNO3? 0.01M
(10)How many milliliters of a stock solution of 2.00M KNO3 would you need to prepare
100.0 mL of 0.150M KNO3? 7.5 ml
(12)How many grams of K2SO4 would you need to prepare 1500 liters of 5.0 M K2SO4
solution? 1,305,000 g K2SO4 or 1.3x106 g K2SO4 or 1,305 kg K2SO4
(16)To 225 mL of a 0.80M solution of KI, a student adds enough water to make 1.0 L of a
more dilute KI solution. What is the molarity of the new solution? 0.18 M
(17)How many mL of a 2.0M NaBr solution are needed to make 200.0 mL of 0.50M NaBr
50 ml
(18)What mass of Na SO is needed to make 2.5 L of 2.0M solution? 710 g Na SO
(19)What is the molarity of Na SO a solution containing 56 grams of solute in 959 mL of
solution? 0.411 M Na SO
(20)Describe how you would prepare 98 mL of 0.50M KCl starting with a stock solution
that is 2.0M KCl a. calc the vol of stock, measure it with a graduated cylinder add half the 98
ml volume w
Matching
1. Concentration C
A. number of moles of solute dissolved in 1 L of solution.
2. Molarity A
B. solute and solvent mixed together.
3. Solubility J
C. measure of the amount of solute that is dissolved in a
given quantity of solvent.
4. unsaturated solution F
D. amount of solute in a given solvent at a specific temperature,
and pressure to produce a saturated solution.
5. Solution B
E. contains more solute than it can hold at a specific temperature.
6. Dilution G
F. contains less solute than it can hold at a specific temperature.
7. supersaturated
solution E
8. a saturated solution D
G. uses less moles than the stock solution.
9. Solute I
I. compound that dissolves in solvent.
10. Solvent H
J. contains the appropriate amount of solute in solution at a
specific temperature and pressure without causing
precipitation.
H. medium in which solutes are found.