ANSWERS TO :
CHAPTER 18 HOW CHEMICALS MIX
Multiple Choice
Identify the choice that best completes the statement or answers the question.
__B__ 1. A combination of two or more substances in which they no longer retain their chemical properties is called
a(n) _____.
a. heterogeneous mixture
d. mixture
b. compound
e. periodic trend
c. suspension
__A_
2. The following image represents which kind of matter?
a. a mixture
b. an element
c. a compound
d. none of the above
e. all of the above
__B__ 3. The following image represents which kind of matter?
a. an element
b. a compound
c. a mixture
__E_
4. Which of the following is a mixture?
a. salt
b. iron
c. gold
d. none of the above
e. all of the above
d. helium
e. air
___C____5.
How does a suspension differ from a solution?
a. A suspension is a heterogeneous mixture consisting of different phases whereas a solution
is a homogeneous mixture consisting of a single phase.
b. The difference between a suspension and a solution can only be determined by chemical
means.
c. Although a solution and suspension are both homogeneous mixtures, only the components
of a suspension will separate by spinning the mixture in a centrifuge.
d. A suspension is a heterogeneous mixture whose components can be separated by simple
filtration. A solution is a homogeneous mixture which cannot be separated by simple
filtration.
__B__ 6. Swimming pool water is best classified as a
a. heterogeneous mixture
b. homogenous mixture
c. pure element
d. pure compound
__E__ 7. Which of the following is a pure substance?
a. orange juice
b. cooking oil
c. duct tape
__A_
d. salt water
e. baking soda
8. In a solution made from one teaspoon of sugar and one liter of water, which is the solute?
a. sugar
d. both sugar and water
b. the teaspoon
e. none of the above
c. water
__A__ 9. In a solution of 77 percent nitrogen and 23 percent oxygen, which is the solvent?
a. nitrogen
d. neither
b. oxygen
e. Gases cannot form solutions.
c. both
__C__ 10. A sample of steel is composed of 5 percent carbon and 95 percent iron. Which is the solvent?
a. carbon
d. Steel is not a solution, it is a mixture.
b. steel
e. A solid cannot be a solvent.
c. iron
__C_ 11. Which of the following solutions is the most concentrated?
a. one liter of water with 1 gram of sugar
b. one liter of water with 2 grams of sugar
c. one liter of water with 10 grams of sugar
d. one liter of water with 5 grams of sugar
e. They all have the same volume.
__C_ 12. How is the solubility of a gas affected by temperature?
a. As temperature goes down, the solubility goes down.
b. As temperature goes up, the solubility stays the same.
c. As temperature goes down, the solubility goes up.
d. As temperature goes up, the solubility goes up.
True/False
Indicate whether the statement is true or false.
__F__ 13. The elements of a compound can be separated from each other by physical means.
__T_ 14. The solubility of a gas in water decreases with increasing temperature.
__T_ 15. A solution is saturated when no more solute can dissolve in that solution.
Matching
a. ELEMENT
b. HOMOGENEOUS MIXTURE
c. HETEROGENEOUS MIXTURE
d. COMPOUND
__A_ 16. Aluminum
__B_ 17. Air (in a small space)
__D_ 18. Distilled water
__B_ 19. Tap water
__D_ 20. Table sugar
__B_ 21. Tea with sugar
__C__ 22. Italian salad dressing
__D_ 23. cabon dioxide
__C_ 24. pizza
__B__ 25. soft drink
__B__ 26. 14 kt gold
__B_ 27. stainless steel
SELECT THE BEST ANSWER- NOT ALL CHOICES WILL BE USED
a. dissolving
f. mixture
b. distillation
g. saturated solution
c. heterogeneous mixture
h. solute
d. homogeneous mixture
i. solvent
e. insoluble
j. unsaturated solution
__J__ 28. a solution that is capable of dissolving additional solute
__C__ 29. a mixture in which the various components can be seen as individual substances
__G__ 30. a solution containing the maximum amount of solute that will dissolve in its solvent
__I_
31. the component in a solution that is present in the largest amount
__B_ 32. a purifyling process in which a vaporized substance is collected by exposing it to cooler temperatures over a
recieving flask, which collects the condensed purified liquid
__A__ 33. the process of mixing a solute in a solvent to produce a homogeneous mixture
__D__ 34. a mixture in which the various compounents are so finely mixed that the composition is the same throughout.
__E__ 35. not capable of dissolveing to any appreciale extent in a given solution.
Essay
36. How might you separate a mixture of sand and salt? How about a mixture of iron and sand?
To separate sand from salt first take advantage of salt’s ability to dissolve by dissolving the mixture in water. The salt will
dissolve but the sand will not. Then pour the mixture through a filter and the sand will be caught in the filter
while the salt water will go through because of the size difference. You can then get the salt out by boiling out
the water taking advantage of the differences in boiling points.
To separate a mixture of iron and sand, take advantage of iron’s property of magnetism and run a magnet repeatedly
through the mixture. The iron will be attracted to the magnet and the sand will not