EP 5 Make up Exam--Write answers in your notebook

you must write the vocab out.

Match each item with the correct statement below.
a. Boyle's law i. Graham's law
b. Charles's law f. Gay-Lussac's law
c. Dalton's law g. ideal gas law

d. effusion h. diffusion
e. compressibility i. partial pressure

f. Henry's law j. supersaturated solution
g. immiscible k concentration
h. saturated solution

____ 1. For a given mass of gas at constant temperature, the volume of the gas varies inversely with pressure.

____ 2. The volume of a fixed mass of gas is directly proportional to its Kelvin temperature, if the pressure is kept constant.

____ 3. The pressure of a gas is directly proportional to its Kelvin temperature if the volume is kept constant.

____ 4. P  V = n  R  T

____ 5. At constant volume and temperature, the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the component gases.

____ 6. The rate at which a gas will effuse is inversely proportional to the square root of the gas’s molar mass.

____ 7. a measure of how much the volume of matter decreases under pressure

____ 8. the pressure exerted by a gas in a mixture

____ 9. the escape of gas through a small hole in a container

____ 10. tendency of molecules to move to regions of lower concentration


____ 11. describes liquids that are insoluble in one another

____ 12. solution containing maximum amount of solute

____ 13. solution containing more solute than can theoretically dissolve at a given temperature

____ 14. At a given temperature, the solubility of a gas in a liquid is directly proportional to the pressure of the gas above the liquid.

____ 15. measure of the amount of solute dissolved in a specified quantity of solvent

Multiple Choice ( 5 points each, 35 points total)
Identify the letter of the choice that best completes the statement or answers the question.

____ 16. To increase the solubility of a gas at constant temperature from 1.20 g/L, at 1.4 atm, to 2.3 g/L, the pressure would have to be increased to ____.
a. 0.37 atm c. 1.37 atm
b. 0.7 atm d. 2.7 atm


____ 17. What is the molarity of a solution containing 7.0 moles of solute in 569 mL of solution?
a. 81M c. 12M
b. 0.081M d. 4.0M


____ 18. What is the molarity of a solution containing 56 grams of solute in 959 mL of solution? (molar mass of solute = 26 g/mol)
a. 1.5M c. 2.1M
b. 2.2M d. 0.0022M


____ 19. The volume of alcohol present in 620 mL of a 40.0% (v/v) solution of alcohol is ____.
a. 372 mL c. 248 mL
b. 40.0 mL d. 580 mL


____ 20. What is the molality of a solution containing 8.0 grams of solute in 0.50 kg of solvent? (molar mass of solute = 24 g)
a. 0.67m c. 1.67m
b. 4m d. 0.17m


____ 21. The freezing point of a solution that contains 0.550 moles of NaI in 615 g of water is ____. (K = 1.86 C/m; molar mass of water = 18 g)
a. 1.66 C c. 3.33 C
b. –1.66 C d. –3.33 C


____ 22. What is the boiling point of a solution that contains 3 moles of KBr in 2000 g of water? (K = 0.512 C/m; molar mass of water = 18 g)
a. 97 C c. 101.4 C
b. 99.7 C d. 103 C


Short Answer (10 points each, 40 points total)

23. The gaseous product of a reaction is collected in a 25.0-L container at 27 C. The pressure in the container is 300.0 kPa and the gas has a mass of 96.0 g. How many moles of the gas are in the container?
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24. What is the pressure exerted by 32 g of O in a 22.0-L container at 30.0 C?
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25. A mixture of gases at a total pressure of 95 kPa contains N , CO , and O . The partial pressure of the CO is 24 kPa and the partial pressure of the N is 48 kPa. What is the partial pressure of the O ?
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26. Use Graham’s law to calculate how much faster fluorine gas, F , will effuse than chlorine gas, Cl , will. The molar mass of F = 38.0; the molar mass of Cl = 70.9.
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Problem (15 pts each, 235 points total)

27. Use kinetic theory to explain why on a cold autumn morning a camper’s air
mattress may appear to be somewhat flatter than when it was blown up the
afternoon before. Assume no leaks.
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28. A sample of O2 with an initial temperature of 50.0C and a volume of 105 L
is cooled to 25C. The new pressure is 105.4 kPa and the new volume is
55.0 L. What was the initial pressure of the sample?
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29. Is it possible for a balloon with an initial pressure of 200.0 kPa to naturally
expand to four times its initial volume when the temperature remains
constant and atmospheric pressure is 101.3 kPa?
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30. A 35.0-L tank contains 7.00 mol of compressed air. If the pressure inside the
tank is 500.0 kPa, what is the temperature of the compressed gas?
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31. What is the volume occupied by 0.355 mole of nitrogen gas at STP?
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32. A gaseous mixture consisting of nitrogen, argon, and oxygen is in a 3.5-L vessel
at 25C. Determine the number of moles of oxygen if the total pressure is 98.5
kPa and the partial pressures of nitrogen and argon are 22.0 kPa and 50.0 kPa,
respectively.
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33. Compare the effusion rates of O2 (molar mass, 32.0 g/mol) and N2 (molar mass,
28.0 g/mol).
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34. The volume of a gas at 155.0 kPa changes from 22.0 L to 10.0 L. What is the
new pressure if the temperature remains constant
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35. 1. In your own words, explain hydrogen bonds.
a. Draw a diagram of the hydrogen bonding between three water molecules.
b. Explain why the density of ice at 0°C is less than the density of liquid water at 0°C.
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36. Which of the following compounds are soluble in water? Which are insoluble?
a. CaCl2
b. N2
c. HBr
d. NH2C2H3O2
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37. 1. Distinguish colloids and suspensions from solutions by discussing their
properties. Classify each of the following mixtures as a colloid, suspension, or solution.
a. fog
b. milk
c. sodium chloride dissolved in water
d. cornstarch in water
e. potting soil shaken with water
f. soap suds
g. a mixture of sucrose and water
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38. The solubility of CO2 in water at 1.22 atm is 0.54 g/L. What is the solubility of
carbon dioxide at 1.86 atm? Assume that temperature is constant.
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39. Calculate the molarity of each of the following solutions.
a. 0.40 mol of NaCl dissolved in 1.6 L of solution
b. 20.2 g of potassium nitrate, KNO3, in enough water to make 250.0 mL of
solution
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40. Calculate the number of grams of solute needed to prepare each of the
following solutions.
a. 2500.0 mL of a 3.0M solution of potassium hydroxide, KOH
b. 2.0 liters of 2.0M nitric acid, HNO3, solution
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41. What is the concentration in percent by volume, %(v/v), of the following
solutions?
a. 60.0 mL of methanol in a total volume of 500.0 mL
b. 25.0 mL of rubbing alcohol (C3H7OH) diluted to a volume of 200.0 mL
with water
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42. What is the boiling point of a solution that contains 2 mol of magnesium
chloride in 100.0 g of water?
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43. Calculate the mole fraction of solute in each of the following solutions.
a. 3.0 moles of lithium bromide, LiBr, dissolved in 6.0 moles of water
b. 125.0 g of potassium nitrate, KNO3, dissolved in 800.0 g of water
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Essay (20 pts each, 60 pts total)

44. What are some of the differences between a real gas and an ideal gas? ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

45. Explain on a particle basis how the addition of a solute affects the boiling point, the freezing point, and the vapor pressure of the solvent. ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________


46. Compare and contrast molarity and molality.
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