jhhjhhjjhhj Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ 1. Which of the following has components that are obviously different? a. homogeneous mixture c. colloid b. solution d. heterogeneous mixture 2. Which of the following is a pure substance? a. water c. soil b. milk d. concrete 3. Which of the following is a heterogeneous mixture? a. water c. whole-wheat bread b. a sugar-water solution d. sugar 4. Which of the following is a homogeneous mixture? a. water c. whole-wheat bread b. a sugar-water solution d. sugar 5. All of the following are heterogeneous mixtures EXCEPT a. whole-wheat bread. c. tap water. b. granite. d. an oil-water mixture. 6. Water in air is an example of which solute-solvent combination? a. gas-liquid c. liquid-liquid b. liquid-gas d. gas-gas 7. Carbon dioxide in water is an example of which solute-solvent combination? a. gas-liquid c. liquid-liquid b. liquid-gas d. cannot be determined 8. Sugar in water is an example of which solute-solvent combination? a. gas-liquid c. solid-liquid b. liquid-liquid d. liquid-solid 9. Oxygen in nitrogen is an example of which solute-solvent combination? a. gas-liquid c. gas-solid b. liquid-gas d. gas-gas 10. Which mixture contains visible particles that settle out unless the mixture is stirred? a. a colloid c. a solution b. a homogeneous mixture d. a suspension 11. Which mixture contains particles that are in a dispersed phase and do not settle out? a. a colloid c. a solution b. a heterogeneous mixture d. a suspension 12. A metal solution is a(n) a. colloid. c. suspension. b. alloy. d. electrolyte. 13. An aerosol dispenser contains a colloidal dispersion of a. two liquids. c. a solid and a liquid. b. two solids. d. a gas and a liquid. 14. A substance whose water solution conducts a current is a(n) a. nonelectrolyte. c. nonpolar substance. b. electrolyte. d. solute. ____ 15. To conduct electricity, a solution must contain a. nonpolar molecules. c. ions. b. polar molecules. d. free electrons. ____ 16. Which of the following is an electrolyte? a. sodium chloride c. water b. sugar d. glass ____ 17. A substance whose water solution does NOT conduct a current is a(n) a. polar substance. c. electrolyte. b. nonelectrolyte. d. ionic substance. ____ 18. Which of the following is a nonelectrolyte? a. sodium chloride c. sugar b. hydrogen chloride d. potassium chloride ____ 19. Increasing the surface area between solute and solvent a. increases the rate of dissolution. b. decreases the rate of dissolution. c. has no effect on the rate of dissolution. d. can increase, decrease, or have no effect on the rate of dissolution. ____ 20. Which of the following decreases the average speed of solvent molecules? a. increasing the temperature c. adding more solvent b. stirring the solution d. decreasing the temperature ____ 21. Which of the following will dissolve most rapidly? a. sugar cubes in cold water c. powdered sugar in cold water b. sugar cubes in hot water d. powdered sugar in hot water ____ 22. Which of the following will dissolve most slowly? a. large salt crystals in unstirred water c. small salt crystals in unstirred water b. large salt crystals in stirred water d. small salt crystals in stirred water ____ 23. Which of the following is at equilibrium when undissolved solute is visible? a. a saturated solution c. a supersaturated solution b. an unsaturated solution d. all of the above ____ 24. If the amount of dissolved solute in a solution at a given temperature is greater than the amount that can permanently remain in solution at that temperature, the solution is said to be a. saturated. c. supersaturated. b. unsaturated. d. diluted. ____ 25. In a solution at equilibrium, a. no dissolution occurs. b. the rate of dissolution is less than the rate of crystallization. c. the rate of dissolution is greater than the rate of crystallization. d. the rate of dissolution and the rate of crystallization are equal. ____ 26. Which of the following is likely to produce crystals if disturbed? a. an unsaturated solution c. a saturated solution b. a supersaturated solution d. a concentrated solution ____ 27. In the expression like dissolves like, the word like refers to similarity in molecular a. mass. c. energy. b. size. d. polarity. ____ 28. Which of the following values for heat of solution at 25ºC represents the greatest release of energy? a. –3.59 kJ/mol c. +1.33 kJ/mol b. –0.01 kJ/mol d. +12.40 kJ/mol ____ 29. Pressure has the greatest effect on the solubility of ____ 30. ____ 31. ____ 32. ____ 33. a. solids in liquids. c. gases in gases. b. liquids in liquids. d. gases in liquids. Effervescence is the a. dissolution of gas in liquid. b. escape of gas from a gas-liquid solution. c. escape of gas from a container of gas. d. escape of solid from a solid-liquid solution. What is the molarity of a solution that contains 0.202 mol KCl in 7.98 L solution? a. 0.0132 M c. 0.459 M b. 0.0253 M d. 1.363 M What is the molarity of a solution that contains 125 g NaCl in 4.00 L solution? a. 0.535 M c. 8.56 M b. 2.14 M d. 31.3 M An NaOH solution contains 1.90 mol of NaOH, and its concentration is 0.555 M. What is its volume? a. 0.623 L c. 1.05 L b. 0.911 L d. 3.42 L Problem 34. A solution contains 85.0 g of NaNO3, and has a volume of 750. mL. Find the molarity of the solution. 35. How many grams of NaOH are required to prepare 200. mL of a 0.450 M solution?
