Question

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Chemistry B Semester Final

1. Particles in a gas are best described as ____. (1 point)
• slow-moving, kinetic, hard spheres
• small, hard spheres with insignificant volumes

2. How does the atmospheric pressure at altitudes below sea level compare with atmospheric pressure at sea level? (1 point)
• The atmospheric pressure below sea level is higher.

Answer 1

3. When a gas is heated, ____. (1 point)
• some of the absorbed energy is converted to potential energy, and some is converted to kinetic energy
• none of the energy is converted to kinetic energy

4. Why does a liquid's rate of evaporation increase when the liquid is heated? (1 point)
• More molecules have enough energy to overcome the attractive forces holding them in the liquid.
• The average kinetic energy of the liquid decreases.

5. Crystals are characterized by particular patterns that repeat in how many dimensions? (1 point)
• three dimensions only
• The patterns do not repeat.

6. Compared to the melting points of ionic compounds, the melting points of molecular solids tend to be ____. (1 point)
• lower
• higher

Answer 2

7. If the volume of a container of gas is reduced, what will happen to the pressure inside the container? (1 point)
• The pressure will increase.
• The pressure depends on the type of gas.

8. When the temperature and number of particles of a gas are constant, which of the following is also constant?
(1 point)
• the difference of the pressure and volume
• the product of the pressure and volume

9. At a certain temperature and pressure, 0.20 mol of carbon dioxide has a volume of 3.1 L. A 3.1-L sample of hydrogen at the same temperature and pressure ____. (1 point)
• has the same mass
• contains the same number of molecules

10. If the atmospheric pressure on Mt. Everest is one-third the atmospheric pressure at sea level, the partial pressure of oxygen on Everest is ____. (1 point)
• one-third its pressure at sea level
• equal to its pressure at sea level

11. The tendency of molecules to move toward areas of lower concentration is called ____. (1 point)
• suffusion
• diffusion

12. What is primarily responsible for the surface tension of water? (1 point)
• dispersion forces
• hydrogen bonding

13. A solution has which of the following properties? (1 point)
• The average diameter of its solute particles usually is less than 1 nm.
• A filter can remove the solute.

14. Which of the following compounds is a weak electrolyte? (1 point)
• NaBr
• NH3

15. The solubility of a gas in a liquid is ____. (1 point)
• proportional to the square root of the pressure of the gas above the liquid
• directly proportional to the pressure of the gas above the liquid

16. What is the molarity of a solution containing 7.0 moles of solute in 569 mL of solution? (1 point)
• 81M
• 12M

17. In which of the following is concentration expressed in percent by volume? (1 point)
• 10% (v/v)
• 10% (m/m)

18. Which of the following is a property of an acid? (1 point)
• sour taste
• strong color

19. What type of acid is sulfuric acid? (1 point)
• monoprotic
• diprotic

20. An indicator is what type of compound? (1 point)
• oxidizing agent
• weak base or acid

21. If an acid has a Ka = 1.6 × 10–10, what is the acidity of the solution? (1 point)
• acidic
• the answer cannot be determined

22. What happens to the energy produced by burning gasoline in a car engine? (1 point)
• The energy is lost as heat in the exhaust.
• The energy is transformed into work to move the car.
• The energy heats the parts of the engine.
• all of the above

23. What is the specific heat of a substance if 1560 cal are required to raise the temperature of a 312–g sample by 15ºC? (1 point)
• 0.33
• 0.99

24. The heat content of a system is equal to the enthalpy only for a system that is at constant ____. (1 point)
• temperature
• pressure

25. The symbol stands for the ____. (1 point)
• heat of reaction for a chemical reaction
• standard heat of formation for a compound

26. A catalyst works by ____. (1 point)
• lowering the activation energy barrier
• shifting the equilibrium position toward the products

27. What happens to a reaction at equilibrium when more reactant is added to the system? (1 point)
• The reaction makes more products.
• The reaction is unchanged.

28. Entropy measures ____. (1 point)
• disorder
• force

29. When iron oxide becomes iron, what type of reaction occurs? (1 point)
• reduction
• neutralization

30. What is the oxidizing agent in the following reaction? CH4 + 2O2 CO2 + H2O (1 point)
• O2
• CO2

31. In the following unbalanced reaction, which atom is oxidized? HNO3 + HBr NO + Br2 + H2O (1 point)
• nitrogen
• bromine

32. Which ion can be most easily reduced? (1 point)
• Cu2+
• Zn2+

33. What occurs in a half-cell? (1 point)
• oxidation only
• oxidation or reduction, but not both

34. Which of the following is true for a dry cell? (1 point)
• The graphite rod does not undergo reduction, even though it is the cathode.
• It can be recharged many times.

35. Which of the following is the name of a process in which electrical energy causes a chemical reaction? (1 point)
• hydrolysis
• electrolysis

36. What occurs in electroplating? (1 point)
• deposition of a salt layer on a metal
• deposition of a metal layer on a material

37. How many valence electrons does a carbon atom have? (1 point)
• 2
• 4

38. What is the molecular formula for an 18-carbon alkane? (1 point)
• C30H18
• C18H38

39. The name for an alkyl group that contains two carbon atoms is ____. (1 point)
• ethyl
• dimethyl

40. Why are the molecules of hydrocarbons nonpolar? (1 point)
• The intermolecular attractions are strong.
• The electron pair is shared almost equally in all the bonds.

41. A saturated straight-chain hydrocarbon with two carbons is ____. (1 point)
• ethene
• ethane

42. A structural isomer of hexane is ____. (1 point)
• 2,2-dimethylbutane
• 2-methylpentene

43. What compound is the simplest aromatic compound? (1 point)
• ethene
• benzene

44. The controlled process by which hydrocarbons are broken down or rearranged into smaller, more useful molecules is called ____. (1 point)
• cracking
• fractionating

45. Differences in ______ account for the variations in properties of peptides and proteins. (1 point)
• amino acid sequences
• Peptide bonds

46. The most important way to classify organic compounds is by ____. (1 point)
• functional group
• the type of carbon—carbon bonds

47. Which of these compounds would you expect to be most soluble in water? (1 point)
• CH3CH2CH2CH3
• CH3CH2CH2OH

48. Aldehydes have the general structure ____________. (1 point)
•
•

49. What is the change in atomic mass when an atom emits a beta particle? (1 point)
• decreases by 1
• remains the same

50. Which symbol is used for an alpha particle? (1 point)
•
•

51. Which type of ionizing radiation can be blocked by clothing? (1 point)
• beta radiation
• alpha radiation

52. The production of carbon-14 ____. (1 point)
• takes place in the upper atmosphere
• occurs to a large extent in nuclear reactors

53. Nuclear fusion ____. (1 point)
• takes place in the sun
• occurs at low temperatures

54. Radioisotopes taken internally for medical reasons ____. (1 point)
• must be eliminated from the body slowly
• should have a short half-life


When submitting an answer in the form of an exponent, use a caret (^) to indicate the power. For example, 53 would be written as 5^3.

55. If the [H+] in a solution is 1 × 10–1 mol/L, what is the [OH–]? Show your work. (3 points)


56. What is the percentage of water in the hydrate CoCl2 • 6H2O? Show your work. (3 points)




57. A rigid container of O2 has a pressure of 340 kPa at a temperature of 713 K. What is the pressure at 273 K? Show your work. (3 points)


58. Explain the difference between temperature and heat. Also, state what determines the direction of heat transfer. (3 points)


59. Describe the structure of the water molecule and indicate how this structure is responsible for many of the unique properties of this vital compound. (5 points)

Answer 3

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