Solutions Practice Test
1. Which of the following substances is less soluble in hot water than in cold water?
a. NaBr
b. KCl
c. LiNO
d. NO
2. Which phrase correctly describes the effect of pressure on the solubility of a gas in a liquid?
a. proportional to the square root of the pressure of the gas above the liquid
b. directly proportional to the pressure of the gas above the liquid
c. inversely proportional to the pressure of the gas above the liquid
d. unrelated to the pressure of the gas above the liquid
3. If the solubility of a solute is
at 20 C, which represents a supersaturated solution of that
solute?
a.
at 25 C
c.
at 20 C
b.
at 15 C
d.
at 20 C
4. What happens to the solubility of a gas in a liquid if the partial pressure of the gas above the liquid
decreases?
a.
The solubility decreases.
c.
The solubility remains the same.
b.
The solubility increases.
d.
The solubility cannot be determined.
5. Which of the following is unchanged when a solution is diluted by the addition of solvent?
a.
volume of solvent
c.
number of moles of solute
b.
mass of solvent
d.
molarity of solution
6. Which of the following compounds provides the most solute particles when completely dissociated in
water?
a. MgCl2
b. KBr
c. C6H12O6,
d. Na3PO3
e. NaCl
7. Which of the following aqueous solutions has the lowest freezing point?
a.
0.10 M potassium chloride, KCl
d.
0.10 M sodium bromide, NaBr
b.
0.10 M hydrochloric acid, HCl
e.
0.10 M sucrose, C12H22O11
c.
0.10 M magnesium chloride, MgCl2
8. Colligative properties depend upon the ____
a.
nature of the solute.
c.
number of solute particles in a solution.
b.
nature of the solvent.
d.
freezing point of a solute.
9. The solubility of potassium chloride is
10.
11.
12.
13.
14.
15.
a.
b.
16.
at 20 C. What is the maximum amount of KCl that
can dissolve in 200 g of water at 20 C?
a. 17 g
b. 34 g
c. 68 g
d. 6800 g
Which of the following generally occurs as temperature increases?
a. Solubility of a solid solute decreases. c. Solubility of a solid solute remains the same.
b. Solubility of a solid solute increases. d. Molarity of a solid solute doubles.
To increase the solubility of a gas at constant temperature from 1.20 g/L, at 1.4 atm, to 2.3g/L, the
pressure would have to be increased to ____.
a. .37 atm
b. 0.70 atm
c. 1.37atm
d. 2.7atm
What is the concentration of a solution that contains 6 moles of solute in 2 liters of solution?
a. 6M
b. 12M
c. 7M
d. 3M
What is the number of moles of solute in 250 mL of a 0.4M solution?
a. 0.1 mol
b. 0.16 mol
c. 0.62 mol
d. 1.6 mol
What mass of sucrose, C H O , is needed to make 500.0 mL of a 0.200M solution?
a. 34.2 g
b. 100 g
c. 17.1 g
d. 68.4 g
Which of the following is a colligative property of a solution?
boiling point elevation c.
vapor pressure increase
melting point elevation d.
freezing point increase
The molality of a solution containing 8.1moles of solute in 4847 g of solvent is ____.
Solutions Practice Test
a. 39m
b. 1.7m
c. 0.17m
d. 598m
17. The freezing point of a solution that contains 0.550 moles of NaI in 615 g of water is ____. K = 1.86
C/m
a.
1.66t Cb.
-1.66 C
c.
-3.33 C Remember # particles
3.33 C d.
∆T = m K i (i is # particles solute dissociates into)
18. What is the boiling point of a solution that contains 3 moles of KBr in 2000 g of water? K = 0.512 C/m
a.97 C b.99.7 C
c.101.4 C d. 103 C Remember # particles add∆ T to 100 C
19. If the solubility of a gas is 7.5 g/L at 404 kPa, what is the pressure of the gas when the solubility is 4.5
g/L?
242 kPa
20. What is the molarity of a solution containing 3.0 moles of solute in 1800 mL of solution?
1.67 M
21. What is the molarity of a solution containing 1.2 grams of solute in 900 mL of solution ? solute:
16g/mole
0.083 M
22. What is the number of moles of solute in 900 mL of a 0.60M solution?
0.54 moles
23. One mL of 6.0M HCl is added to 499 mL H2O making a 500.0-mL solution, what is the M of the dilute
solution?
(1 ml) (6.0M) = x(500ml) x=0.012 M
24. What is the molality of a solution with 3.0 moles of solute in 2.8 kg of solvent? Moles/Kg solvent = molality
1.07m
25. What is the freezing point of a solution that has 2.0 moles of CaBr2 in 1250 g of water? K = 1.86 C/m
1.6m ( 1.86) (3) = 8.9 °C [3 is the number of particles Ca Br2 dissociates into] Freezing point of pure
water is 0 °C. Depression means lower so subtract. -8.9°C
26.List three ways that the rate of solvation of a solid may be increased (and explain how).
Add heat, agitate, reduce particle size. All increase number of collisions between solute and solvent
27. What is the mole fraction of ethanol in a solution of 2.00 moles of ethanol and 15.00 moles of water?
0.12
28How would you correctly prepare 200 mL of a 0.20M solution of iron(II) nitrate (Fe(NO3)2) from a 2.00M
solution of Fe(NO3)2? Be very specific.
(200ml)(0.20M) = (xml) (2.00M) x = 20ml
Put 20 ml of concentrated solution in a flask; bring the
volume to 200ml. Mix thoroughly.
29. The graph below shows the solubility versus temperature for four compounds, A, B, C, D. Comment on
the difference between Solution A and Solution D. Explain this difference.
Solution A increases in solubility as the temperature increases. Solution D decreases in solubility as the
temperature increases. Solution D is most likely a gas.
30. Draw a detailed diagram showing the solvation of KBr in water.
see next page
Solutions Practice Test
K+
K+
BrBr-
K+