Chapter 12 Test Review Guide
1. Explain why chemical compounds tend to dissolve more quickly in hot solvent than in
cold solvent.
2. Why does agitating the solution speed up the rate of dissolution?
3. What is the third way to speed up the rate of dissolution?
4. What is the molarity of a solution made when you dilute 35 grams of sodium carbonate
to a volume of 3,400 mL?
5. What is the molarity when 9.59 g of sodium chloride (NaCl) dissolved in enough water to make
1.35 L of solution?
6. What volume of 0.250 M solution of BaCl2 do you need to use to make 500. mL of 0.500 M
solution?
7. What is the molarity of each ion in 0.050 M solution of CaCl2?
8. How many moles of ions are produced by dissociation of 4.40 mol Na3PO4?
9. How many moles of ions are in 450 mL of 0.03M solution of KF?
10. How many moles of ions are in 200. mL of .250 M solution of (NH4)2SO4?
11. How many moles of ions are in 150 mL of .350 M solution of AlCl3?
12. How many moles of ions are produced by dissociation of 1.0 mol of MgF2?
13. How many moles of ions are produced by dissociation of 2.50 mol of Ca3(PO4)2?
14. How many moles of ions are produced by dissociation of 5.80 mol of BeCl2?
15. How many moles of ions are in 240 mL of 3.54M solution of Al3S2?
16. How many moles of ions are in 340 mL of 2.50 M solution of AgNO3?
17. How many moles of ions are in 790 mL of 3.40 M solution of PbCl2?
18. What is the molarity of a solution of ammoniium phosphate prepared by diluting 100. mL of
a 3.90 M solution to 4.00 L?
19. To what volume should 2.20 mL of an 6.00 M acetic acid solution be diluted in order to
obtain a final solution that is 1.50 M?
20. A 10.00 mL sample of ammonium nitrate solution produces a 0.304 M solution when diluted
with 50.00 mL of water. What is the molarity of the stock solution?
21. A chemist prepares 480. mL of 4.50 M solution of KCl in water. A week later, the chemist
wants to use the solution, but the stopper has been left off the flask and 100. mL of water has
evaporated. What is the new molarity of the solution?
22. A chemical test has determined the molarity of a solution of an unknown substance to be
2.41 M. A 100.0 mL volume of the solution is evaporated to dryness, leaving 9.56 g of crystals of
the unknown solute. Calculate the molar mass of the unknown substance.
23. A student wants to prepare 600. mL of s stock solution of 2.0 M copper (II) chloride solution.
What mass of CuCl2 should be used to make the solution?
24. A student wants to make 0.150 M aqueous solution of silver nitrate, AgNO3 and has a bottle
containing 12.25 grams of silver nitrate. What should be the final volume of the soluteion?
25. What mass of barium nitrate is dissolved in 20.30 mL of 4.50 M solution?
26. What mass of anhydrous cobalt (II) chloride would be needed in order to make 550. mL of
2.50 M cobalt (II) chloride solution?
27. What is the new molarity of each ion when 500. mL of 3.50 M solution of CaCl2 is diluted
with 200. mL of water?
28. What is the new molarity of each ion when 250. mL of 2.50 M solution of K 3PO4 is diluted to
500. mL of water?
29. What is the new molarity of each ion when 150. mL of 1.50 M solution of AlCl3 is diluted to
400. mL of water?
30. What is the new molarity of each ion when 50. mL of 7.0 M NaCl solution is diluted with 100.
mL of water?
31. Provide an example of an electrolyte and a nonelectrolyte and explain the difference
between the two.
32. Given the Beer’s law plot, find the molarity of a solution with an absorbance value of 0.026
0.06
Beer's law Plot
Absorbance
0.05
0.04
0.03
Series1
0.02
Linear (Series1)
0.01
0
0
0.5
Molarity (M)
1
1.5
Use your solubility curve graph provided to answer the following questions.
1. What are the units of solubility on solubility curves? ___________
2. Define solubility. __________________________________________________
3. According to the graph, the solubility of any substaas _________
changes.
4. List the substances whose solubility decreases as temperature increases.
___________
5. Which substance is least affected by temperature changes?
____________________
6. How many grams of ammonium chloride (NH4Cl) at 50°C?
______________________
7. _____________ and ____________ have the same solubility at approximately
78°C.
8. Which compound is least soluble in water at 10°C? ___________
9. How many grams of KNO3 can be dissolved at 50°C? __________
10. Are the following solutions unsaturated, saturated, or supersaturated?
a. 45g of NaNO3 in 100 g of water at 30°C.____________
b. 60g of KClO3 in 100 g of water at 60°C.____________
11. How many grams of sodium chloride, NaCl are required to saturate 100 grams of
water
at 100° C? __________
12. How many grams of NaNO3 are required to saturate 100 grams of water at
90°C?____
13. How many grams of KI will saturate water at 20°C?________
14. At what temperature would 25g of potassium chlorate (KClO3) dissolve? _______
15. At what temperature would 55g of NH4Cl dissolve? ________
16. 89 g NaNO3 is prepared at 30°C.
a) Will all of the salt dissolve? ____________
b) What mass of NaNO3 will dissolve at this temperature? __________
17. If 25 grams of NH4Cl is dissolved at 50°C, how many additional grams NH4Cl would
be needed to make the solution saturated at 80°C? _________
18. At 50°C, how many grams of KNO3 will dissolve? _________
19. At 70°C, how many grams of cerium (III) sulfate (Ce2(SO4)3) dissolve? __________
20. Determine if each of the following is unsaturated, saturated, or supersaturated.
a. 55g of NH3 at 20°C._________ f. 80g of NaNO3 at 10°C. ._________
b. 10g of Ce2(SO4)3 at 10°C._________ g. 145g of NaNO3 at 80°C. ._________
c. 125g of KNO3 at 60°C. _________ h. 35g of NaCl at 100°C._________
d. 65g of NH4Cl at 80°C. _____________
e. 12g of NH3 at 90°C. ______________