Download DUE: Tuesday, Jan. 20, 2015 Solutions Take Home Test

Name: _____________________________________
DUE: Tuesday, Jan. 20, 2015
Solutions Take Home Test
Matching
Match each item with the correct statement below.
a. solvation
e. electrolyte
b. weak electrolyte
f. colloid
c. aqueous solution
g. surfactant
d. solvent
____ 1. interferes with hydrogen bonding between water molecules
____ 2. dissolving medium
____ 3. homogeneous mixture of water and dissolved substances
____ 4. Solute ions or molecules are surrounded by solvent molecules.
____ 5. compound that will conduct current in the liquid state or in aqueous solution
____ 6. compound that ionizes incompletely in aqueous solution
____ 7. mixture in which particle size averages between 1 nm and 1000 nm
Match each item with the correct statement below.
a. Henry's law
d. supersaturated solution
b. immiscible
e. concentration
c. saturated solution
____ 8. solution containing maximum amount of solute
____ 9. solution containing more solute than can theoretically dissolve at a given temperature
____ 10. measure of the amount of solute dissolved in a specified quantity of solvent
Match each item with the correct statement below.
a. boiling point elevation
d. molarity
b. molality
e. freezing point depression
c. mole fraction
____ 11. number of moles of solute dissolved in 1 L of solution
____ 12. a colligative property related to the fact that ice will form at higher temperatures in the Great
Lakes than in the ocean
____ 13. a colligative property related to a decrease in the vapor pressure of a solution
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 14. How does the surface tension of water compare with the surface tensions of most other liquids?
a. It is lower.
b. It is about the same.
c. It is higher.
d. It is higher only when a surfactant is added.
____ 15. What causes water's low vapor pressure?
a. dispersion forces
b. covalent bonding
c. hydrogen bonding
d. ionic attractions
____ 16. What is the shape of the water molecule?
a. linear
b. tetrahedral
c. trigonal planar
d. bent
____ 17. Which of the following is primarily responsible for holding water molecules together in the liquid
state?
a. dispersion forces
b. hydrogen bonds
c. ionic bonds
d. polar covalent bonds
____ 18. Which atom in a water molecule has the greatest electronegativity?
a. one of the hydrogen atoms
b. both hydrogen atoms
c. the oxygen atom
d. There is no difference in the electronegativities of the atoms in a water molecule.
____ 19. The bonds between adjacent water molecules are called ____.
a. hydrogen bonds
b. ionic bonds
c. nonpolar covalent bonds
d. polar covalent bonds
____ 20. How much heat is absorbed when 6.30 g of water melts?
a. 21 kJ
b. 0.210 kJ
c. 2.10 kJ
d. 21.0 J
____ 21. What is the term for the dissolving medium in a solution?
a. solvent
b. solute
c. solvator
d. emulsifier
____ 22. A solution is a mixture
a. from which the solute can be filtered.
b. that has the same properties throughout.
c. that is heterogeneous.
d. in which a solid solute is always dissolved in a liquid solvent.
____ 23. Which symbol is used to connect the formula of the compound with the number of water
molecules in a hydrate?
a. a parenthesis
b. an asterisk
c. a multiplication symbol
d. a dot
____ 24. What is the size range of particles in a colloid?
a. more than 1000 nm
b. between 100 nm and 1000 nm
c. between 1 nm and 1000 nm
d. between 1 nm and 10 nm
____ 25. Which of the following usually makes a substance dissolve faster in a solvent?
a. agitating the solution
b. increasing the particle size of the solute
c. lowering the temperature
d. decreasing the number of particles
____ 26. The solubility of potassium chloride is
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
____ 27. How does shaking or stirring a mixture of solute and solvent affect a solution?
a. It increases the rate of dissolving.
b. It decreases the rate of dissolving.
c. It increases the solubility of the solute.
d. It decreases the solubility of the solute.
____ 28. Which of the following factors affect solubility?
a. temperature and the nature of the solvent
b. temperature and degree of mixing
c. particle size and degree of mixing
d. particle size and temperature
____ 29. Which of the following substances is less soluble in hot water than in cold water?
a. CO
b. NaCl
c. NaNO
d. KBr
____ 30. Which of the following generally occurs as temperature increases?
a. Solubility of a solid solute decreases.
b. Solubility of a solid solute increases.
c. Solubility of a solid solute remains the same.
d. Molarity of a solid solute doubles.
____ 31. 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
____ 32. What is the concentration of a solution?
a. a measure of the number of moles of solute dissolved
b. a measure of the amount of solute in a specified quantity of solvent
c. a measure of the volume of solvent used to make the solution
d. a measure of the amount of solute that can be dissolved
____ 33. 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
____ 34. What is the molarity of a solution containing 7.0 moles of solute in 569 mL of solution?
a. 81M
b. 0.081M
c. 12M
d. 4.0M
____ 35. 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
____ 36. 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
b. 2.2M
c. 2.1M
d. 0.0022M
____ 37. Which of the following is unchanged when a solution is diluted by the addition of solvent?
a. volume of solvent
b. mass of solvent
c. number of moles of solute
d. molarity of solution
____ 38. How many mL of a 2.0M NaBr solution are needed to make 200.0 mL of 0.50M NaBr?
a. 25 mL
b. 50 mL
c. 100 mL
d. 150 mL
____ 39. If 2.0 mL of 6.0M HCl is used to make a 500.0-mL aqueous solution, what is the molarity of the
dilute solution?
a. 0.024M
b. 0.24M
c. 0.30M
d. 0.83M
____ 40. If the percent by volume is 2.0% and the volume of solution is 250 mL, what is the volume of solute
in solution?
a. 0.5 mL
b. 1.25 mL
c. 5.0 mL
d. 12.5 mL
____ 41. If the percent (mass/mass) for a solute is 4% and the mass of the solution is 200 g, what is the mass
of solute in solution?
a. 8.0 g
b. 50 g
c. 80 g
d. 800 g
____ 42. In which of the following is concentration expressed in percent by volume?
a.
100%
b.
c.
d.
100%
100%
100%
____ 43. Which of the following is a colligative property of a solution?
a. boiling point elevation
b. melting point elevation
c. vapor pressure increase
d. freezing point increase
____ 44. Colligative properties depend upon the ____
a. nature of the solute.
b. nature of the solvent.
c. number of solute particles in a solution.
d. freezing point of a solute.
____ 45. The molality of a solution containing 8.1 moles of solute in 4847 g of solvent is ____.
a. 39m
b. 1.7m
c. 0.17m
d. 598m
Short Answer
46. At what temperature does liquid water have its maximum density?
47. What is the percentage of water in the hydrate CoCl
48. What mass of KCl (solubility =
6
?
at 20 C) can dissolve in 3.30
10 g of water?
49. How many liters of a 0.30M solution are needed to give 2.7 moles of solute?
50. What is the molarity of a solution containing 9.0 moles of solute in 2500 mL of solution?
51. What is the molarity of a solution containing 1.2 grams of solute in 450 mL of solution? (molar mass
of solute = 24 g)
52. What is the number of moles of solute in 650 mL of a 0.40M solution?
53. How many liters of a 1.5M solution are required to yield 5.0 grams of solute? (molar mass of solute
= 30.0 g)
54. If 1.0 mL of 6.0M HCl is added to 499 mL of water to give exactly a 500-mL solution, what is the
molarity of the dilute solution?
55. How many hydrogen bonds can be formed between one hydrogen atom in a water molecule and
oxygen atoms of surrounding water molecules?
Essay
56. Define the terms solute, solvent, and aqueous solution. Provide an example of each.
57. What is an electrolyte? Give examples and distinguish between a strong electrolyte and a weak
electrolyte.
58. Explain what a saturated solution is. Give a specific example.
59. Discuss the different factors that can affect the solubility of a substance. Include specific examples
in your discussion