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Chemistry Review Quiz

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Chemistry Review Quiz

Multiple Choice

Identify the letter of the choice that best completes the statement or answers the question.

____ 1. Homeostasis means

a. a change over long periods of time. c. rapid change.

b. keeping things the same. d. the same thing as evolution.

____ 2. Dr. Ross knew that the parasite Plasmodium was always found in the blood of malaria patients. He thought that if the Anopheles mosquitoes were responsible for spreading malaria, then Plasmodium would be found in the mosquitoes. This idea was a

a. prediction. c. theory.

b. hypothesis. d. scientific “truth.”

____ 3. The electrons of an atom

a. are found in the nucleus along with the protons.

b. orbit the nucleus in various energy levels.

c. have a positive charge.

d. are attracted to the positive charge of neutrons.

____ 4. Atoms that have gained energy

a. have protons and neutrons that move farther apart.

b. lose neutrons from the nucleus.

c. have electrons that move to higher energy levels.

d. absorb electrons into the nucleus.

____ 5. The bond formed when two atoms share a pair of electrons is called a

a. hydrogen bond. c. covalent bond.

b. nonpolar bond. d. water bond.

____ 6. Buffers

a. are of relatively little importance in living things.

b. are formed when a large number of hydroxide ions are released in a solution.

c. are formed when a large number of hydronium ions are released in a solution.

d. tend to prevent great fluctuations in pH.

____ 7. Nonpolar molecules have

a. no negative or positive poles. c. only a negative pole.

b. both negative and positive poles. d. only a positive pole.

____ 8. Water is important to life because it a. surrounds all cells.

b. is found inside cells.

c. influences the shape of the a membrane.

d. All of the above

____ 9. Water is a polar molecule because

a. it contains two hydrogen atoms for each oxygen atom.

b. it has a charge.

c. different parts of the molecule have slightly different charges.

d. it does not have a charge.

____ 10. All organic compounds contain the element

a. C. c. Ca.

b. N. d. Na.

____ 11. Carbon is different from most other elements in that

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a. it has four electrons in its outermost energy level.

b. it readily bonds with other carbon atoms.

c. it can form single, double, or triple bonds with other atoms.

d. it shares two electrons with another atom when it forms a covalent bond.

Assume that each of the atoms below requires eight electrons to fill its outer energy level.

____ 12. Refer to the illustration above. Which of the atoms is chemically stable?

a. Atom “A” c. Atom “C”

b. Atom “B” d. None of the above

____ 13. Refer to the illustration above. If Atom “C” interacted with Atom “B” to form an ionic bond, Atom “C”

would

a. lose 6 electrons. c. gain 5 electrons.

b. gain 2 electrons. d. move 4 electrons into the nucleus.

____ 14. Refer to the illustration above. If Atom “B” interacted with Atom “C” to form an ionic bond, Atom “B”

would

a. gain 6 electrons. c. lose 2 electrons.

b. lose 4 electrons. d. move 2 electrons into the nucleus.

____ 15. An atom that has gained or lost electrons is called a(n)

a. molecule. c. ion.

b. nucleon. d. element.

____ 16. Which of the following statements most accurately describes the difference between an ionic bond and a covalent bond?

a. Atoms held together by ionic bonds separate when placed in water while atoms held together by covalent bonds do not separate in water.

b. Ionic bonds hold together atoms of two different types, while covalent bonds hold together atoms of the same type.

c. Electrons are exchanged between atoms held together by an ionic bond, but they are shared between atoms held together by a covalent bond.

d. Ionic bonds form between atoms that carry opposite charges, while covalent bonds form between uncharged atoms.

____ 17. A reaction in which the products have less energy than the reactants is a. an endergonic reaction. c. a filamentous reaction.

b. an exergonic reaction. d. impossible.

____ 18. If the products of a chemical reaction contain less energy than the reactants, the reaction must a. involve the release of energy. c. be an energy-storing reaction.

b. result in the production of sugar. d. occur in the cytoplasm of cells.

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____ 19. Refer to the graph above. Reaction “1” in the graph a. is an energy-storing reaction.

b. requires a greater activation energy than Reaction “2.”

c. may use the same initial reactant condition needed to form Product “B.”

d. All of the above

____ 20. Refer to the graph above. Reaction “3” in the graph a. probably occurred in the presence of a catalyst.

b. requires a greater activation energy than Reaction “2.”

c. is the same as Reaction “1,” but faster.

d. takes longer than Reaction “2.”

____ 21. Refer to the graph above. Which of these statements is true regarding the graph?

a. Reaction “2” occurs faster than Reaction “3” because Reaction “2” requires more energy than Reaction “3.”

b. The difference in the graphs shown for Reaction “2” and Reaction “3” is due to a difference in the activation energy needed for these reactions.

c. Reactant “A” contains more energy at the beginning of the reaction than Product “C” has after the reaction.

d. All of the above

____ 22. Refer to the graphs above. Which graph illustrates what happens during an exergonic reaction?

a. Graph “A”

b. Graph “B”

c. Both graphs; they each show a different stage of an exergonic reaction.

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d. Neither graph shows an exergonic reaction.

____ 23. Refer to the graphs above. Which graph illustrates a reaction during which reaction energy is released into the environment?

a. Graph “A”

b. Graph “B”

c. Both graphs, since all chemical reactions release energy into the environment d. Neither graph, since chemical reactions do not involve energy

____ 24. Changing the course or pathway of a chemical reaction so that it requires less activation energy a. is a violation of the laws of nature.

b. requires higher temperatures than those found within cells.

c. occurs only when reactants are quickly added to the reaction mixture.

d. is accomplished by the action of catalysts on reactants.

____ 25. Oxidation-reduction reactions are important in organisms because they a. allow the passage of energy from molecule to molecule.

b. prevent nuclear reactions from occurring.

c. allow the creation and destruction of energy.

d. None of the above; oxidation-reduction reactions do not occur in living organisms.

____ 26. The concentration of a solution is

a. the number of particles of a substance in a solution.

b. the amount of a solvent that is dissolved in a fixed amount of a solution.

c. the amount of a solute that is dissolved in a fixed amount of a solution.

d. the ratio of solute to solvent in a solution.

____ 27. A neutral solution has an equal number of

a. hydrogen and hydronium ions. c. hydrogen and hydroxide ions.

b. hydroxide and hydronium ions. d. oxygen and hydrogen ions.

____ 28. The terms base and alkaline refer to solutions that a. contain dissolved sodium hydroxide.

b. contain more hydronium ions than hydroxide ions.

c. contain more hydroxide ions than hydronium ions.

d. contain more hydroxide ions than hydrogen ions.

____ 29. A solution with a pH of 11 is

a. acidic. c. neutral.

b. basic. d. a buffer.

____ 30. Acidic solutions have a pH that is

a. less than 7. c. a negative number.

b. between 0 and 14. d. more than 7.

____ 31. Which of the following is characteristic of all living things?

a. movement c. development

b. growth d. cellular organization

____ 32. Which example of scientific methodology is incorrect?

a. Observation—A number of people in Zaire dying of a disease outbreak

b. Measurement—A record of the number of people with symptoms of the disease and the number of people who had died from the disease

c. Analysis of data—Comparison of the effects of mixing monkey cells with virus-

containing blood in test tubes and the effects of mixing of liquid from these test tubes with fresh monkey cells

d. Inference making—Identification of the Ebola virus as the cause of the disease by taking electron micrographs of substances found in the blood of persons affected with the disease ____ 33. Most typically, the order in which the steps of the scientific method are applied is

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a. observations, predictions, hypothesis, controlled testing, theory, verification.

b. predictions, observations, hypothesis, theory, controlled testing, verification.

c. observations, hypothesis, predictions, controlled testing, theory, verification.

d. observations, hypothesis, predictions, controlled testing, verification, theory.

____ 34. A light microscope that has an objective lens of 10 and an ocular lens of 20 has a magnification of

a. 30. c. 300.

b. 200. d. 2000.

Problem

35. Some scientists conducted an experiment in which they evaluated various measurements of human health in people who drank at least one cup of coffee a day. They found no significant differences in these health indicators in the subjects who drank only one cup of coffee a day and those who drank as many as 20 cups a day. They concluded that coffee has no adverse effects on human health. Write your answers to the following in the spaces below.

a. What were the independent and dependent variables in this experiment?

b. Was this a controlled experiment? If so, what were the control and experimental groups?

c. Do you agree with the conclusion the scientists’ drew from their results? Why or why not?

36. You need to clean up a spill of Hydrochloric acid of an unknown molarity. You estimate that 500 ml spilled.

You find that 1000 ml of 3 M sodium hydroxide neutralizes the spill. What is the molarity of the hydrochloric acid?

37. Hydrogen and Chlorine react to yield hydrogen chloride. How many grams of hydrogen chloride are formed from the reaction of 3.56 g of hydrogen gas with 8.94 g of chlorine? which reactant is limiting?

A. Write the balanced chemical reaction

B. Determine the formula masses of hydrogen gas, chlorine and hydrogen chloride (amu)

C. Using A and B, figure out the limiting reagent.

38. Explain how one would make a 0.5 M solution of sodium chloride. How many atoms of sodium chloride does this represent?

Essay (Short Answer...tables, bullets ok!)

39. Plant growers often use sprinkler irrigation to protect crops they are growing from frost damage. The water that lands on the leaves turns to ice. How does this protect the plants from frost damage? Write your answer in the space below. (Hint: Be sure to mention why hydrogen bonds are responsible for this

phenomenon.)

40. Name five characteristics that are considered distinct properties of all living things. Write your answer in the space below.

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41. The text states that the percentages of naturally occurring elements making up the human body (see TABLE 2.1) are similar for other organisms. How could you account for this similarity among organisms?

42. What is a blood buffer? How does the pH scale relate to blood buffering?

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References

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