Chapter 3 Review Page 74 - 75

6. The ________ is the substance that dissolves to form a solution.

Answer: Solute

2. The ability of one substance to dissolve in another substance is the _______ of the solute.

Answer: Solubility

5. A(n) _________ is an element that is brittle and dull.

Answer: Nonmetal

1. A(n) ________ has a definite ratio of components.

Answer: Compound

4. A(n) _______ is a pure substance that cannot be broken down into simpler substances by chemical means.

Answer: Element

3. A(n) _______ can be separated by filtration.

Answer: Suspension

8. Which of the following best describes chicken noodle soup?

Answer: B

11. Which of the following substances can be separated into simpler substances only by chemical means?

Answer: C

7. Which of the following increases the solubility of a gas in a liquid?

Answer: C

9. Which of the following statements describes elements?

Answer: C

12. Which of the following would not increase the rate at which a solid dissolves?

Answer: A

10. A solution that contains a large amount of solute is best described as _______.

Answer: B

14. An element that conducts thermal energy well and is easily shaped is a _______.

Answer: A

13. In which classification of matter are components chemically combined?

Answer: C

16. When nail polish is dissolved in acetone, which substance is the solute, and which is the solvent?

Answer: Nail polish is the solute, acetone is the solvent.

15. What is the difference between an element and a compound?

Answer: Elements cannot be separated into simpler substance, but compounds can be separated by chemical means.

18. How many grams of sugar must be dissolved in 150 mL of water to make a solution that has a concentration of 0.6 g/mL?

Answer: 150mL x 0.6 g/mL = 90 g

17. What is the concentration of a solution prepared by mixing 50 g of salt with 200mL of water?

Answer: 50g/200mL = 0.25 g/mL

20. To keep the “fizz” in carbonated beverages after they have been opened, should you store them in a refrigerator or in a cabinet? Explain.

Answer: Carbonated beverages should be stored in a refrigerator Answer: Carbonated beverages should be stored in a refrigerator. Gases are more soluble at lower temperatures, so more gas will stay dissolved in the beverage if it is kept cold.

19. Use the following terms to create a concept map: matter, element, compound, mixture, solution, suspension, and colloid.

Answer: Matter Element Mixture Compound Colloid Suspension Solution

23. Describe a procedure to separate a mixture of salt, finely ground pepper, and pebbles.

Answer: Pass the mixture through a screen that allows the salt and pepper to pass through but traps the pebbles. Mix the salt and pepper with water to dissolve the salt. Filter the mister to trap the Perrier. Evaporate the water to recover the salt.

21. A light green powder is heated in a test tube 21. A light green powder is heated in a test tube. A gas is given off, and the solid becomes black. In which classification of matter does the green powder belong? Explain your reasoning.

Answer: The powder is a compound Answer: The powder is a compound. The change in color and the formation of a gas imply that a chemical change took place. Compounds can be broken down by chemical changes.

22. Why is it desirable to know the exact concentration of solutions rather than whether they are concentrated or dilute?

Answer: the exact concentration tells you exactly how much solute is dissolved in the solvent. Concentrated and dilute are descriptive terms that do not tell you the amount of solute.

24. Use a computer or graph paper to construct a graph of Dr 24. Use a computer or graph paper to construct a graph of Dr. Vent’s results. Examine the graph. To increase the solubility, would you increase or decrease the temperature? Explain.

Answer: You should decrease the temperature to increase the solubility Answer: You should decrease the temperature to increase the solubility. As the temperature decreases, more solute can dissolve.

25. If 200mL of water were used instead of 100 mL, how many grams of the compound would dissolve at 40 degrees C.

Answer: 68 g

26. Based on the solubility of this compound, is this compound a solid, liquid, or gas? Explain your answer.

Answer: Because the solubility increases as the temperature decreases, the solute is most likely a gas.