Chemcom Unit 4 Exam . . . Air: Chemistry and the Atmosphere

 

True/False (Choose the best answer.)

  1. Carbon dioxide, CO2, is the major component of air.


  2. Gas pressure arises from gas molecules colliding with objects.


  3. As the pressure of a gas increases, its volume decreases.


  4. As the temperature of a gas increases, its volume decreases.


  5. When performing calculations with gases, it is important to convert temperature units to Kelvins.


  6. As the temperature of a gas increases, the particles of the gas tend to increase their speeds.


  7. One mole of a gas at 25 oC and 1 atm occupies 22.4 Liters.


  8. In the reaction, 2 H2 (g) + O2 (g) 2 H2O (g), 2 liters of H2 will react completely with one liter of O2.


  9. In the reaction, 2 H2 (g) + O2 (g) 2 H2O (g), 4 liters of H2 will react completely to form 2 liters of of H2O.


  10. Wavelength is the distance between identical parts of adjacent waves.


  11. As the wavelength of a light wave increases, the frequency of the wave also increases.


  12. Gama, X-rays, and Radio waves are the most common types of electromagnetic radiation to strike the earth's surface.


  13. Most of the light that strikes the earth's surface is used in photosynthesis.


  14. Of the light that is absorbed by the earth's surface, some is re-radiated as IR radiation to the atmosphere.


  15. A greenhouse gas is a gas that aborbs ultraviolet radiation.


  16. Specific heat is defines as the amount of energy to raise 1 gram of a substance 1 o Celsius.


  17. The specific heat of water (1 cal / (g o C) or 4.2 J / (g o C ) ) is relatively large compared to other substances.


  18. In the Carbon Dioxide Levels Lab, most students found that the CO2 in atmospheric gases was greater than that from exhaled breath.


  19. Acid rain is fog, sleet, or show that has a pH higher than 5.6.


  20. Acid rain results when the gases CO2, SO2, and NOX dissolve in water vapor.


  21. The primary source of SO2 is stationary sources (power plants)


  22. In the acid rain lab, carbon dioxide dissolved in water as shown in the reaction, CO2 + H2O OH -1 + HCO2 -1.


  23. Ca(OH)2 is probably a base.


  24. When an acid neutralizes a base, the likely products are salt and water.


  25. Acids have high pH values.


  26. A solution with a concentration of H +1 = 10 - 3 M has a pH of 3.


  27. A dilute acid has few molecules in a given volume of solution.


  28. A strong acid has lots of molecules in a given volume of solution.


  29. Primary air pollutants enter the air directly and secondary air pollutants form when primary pollutants undergo atmospheric chemical reactions.


  30. Ozone at higher elevations protects earth's surface from UV radiation, but ozone at the surface of the earth is harmful to plants and animals.


Multiple Choice (Choose the best answer.)

 

The diagram at right shows the temperature of the atmosphere at various altitudes. Use the graph to answer questions 1 and 2.

 

 

 

 

 

     

  1. Which statement below best describes the Temperature vs. Altitude graph?

    The temperature increases steadily as the altitude increases.

    The temperature decreases steadily as the altitude increses.

    There seems to be different "zones" in the atmosphere, where Temperature vs. Altitude have different relationships.

    None of the above are correct.

  2. The troposphere is the region of the atmosphere closest to the earth's surface and is responsible for most of the weather experienced on the earth's surface. What range of altitudes contains the troposphere?

    0 - 20 Km

    0 - 50 Km

    0 - 70 Km

    20 - 50 Km

  3. Which of the units below is NOT used to measure gas pressure?

    atmospheres (atm)

    Pascals (Pa)

    Newtons ( N )

    millimeters of mercury ( mm Hg )


    Use the graphs below to answer questions 4 and 5.

  4. Which graph shows the relationship between pressure and volume (Boyle's Law)?

  5. Which graphs shows the relatiohsip between temperature and volume (Charles' Law)?

  6. A gas with a volume of 15 mL at 2 atm of pressure would have what volume at 6 atm of pressure?

    30 mL

    5 mL

    45 mL

    1.3 mL

  7. Human body temperature is about 37 o C. What is this temperature in Kelvins?

    98.6 K

    - 236 K

    310 K

    0.037 K

  8. A gas with a volume of 15 mL at a temperature of 50 oC would have what volume at a temperature of 150 oC?

    45 mL

    5 mL

    20 mL

    500 mL

  9. The mass of one mole of oxygen gas (O2) is 32 g. The volume of one mole of a gas at standard temperature and pressure (STP) = 22.4 L. What would be the volume of 80 g of oxygen gas?

    56 L

    0.11 L

    9.0 L

    110 L

  10. Organize the following types of light from shortest to longest wavelength.

    I. Ultraviolet

    II. Microwaves

    III Infrared

    IV. Visible

    I < II < III < IV

    II < I < III < IV

    II < I < IV < III

    I < IV < III < II

  11. Ultraviolet light is largely prevented from striking the earth's surface because of the presence of _____ in the atmosphere.

    clouds

    ozone

    carbon dioxide

    CFCs

  12. Which of the gases listed below are greenhouse gases.

    I. CO2

    II. H2O

    III. CH4 (Methane)

    IV. CFCs

    I only

    I and II only

    I, II, and III only

    I, II, III, and IV only

  13. The greenhouse effect is the result of _______.

    ultraviolet light being absorbed in the atmosphere by ozone.

    infrared light being reflected from the earth's surface being trapped by gases sucn as CO2 and CH4.

    ultraviolet light increasing the rate of evaporation.

    infrared light being absorbed in the atmosphere by a variety of gases.

    Speciifc heats of various substances are listed in the table below. Use these values for questions 14 - 16.

    Substance

    Water

    Iron

    Lead

    Specific Heat ( J / ( g oC )

    4.2

    0.45

    0.13

  14. If given the same amount of heat, equal masses of which substance would increase its temperature the most?

    Water

    Iron

    Lead

    It is impossible to tell with this information.

  15. How much heat energy would it take to increase the temperature 10 g of water by 20 oC?

    0.021 J

    8400 J

    2.1 J

    8.4 J

  16. If 260 J of heat were added to a 50 g piece of lead, how much would it increase its temperature?

    5.2 oC

    40 oC

    0.68 oC

    1690 oC

  17. The carbon cycle consists of two cycles . . .

    one is geological and the other is biological.

    one moves very slowly and the other is rapid.

    one is very stable and the other is putting increasing amounts of carbon into the atmosphere.

    All of the above are true.

  18. The amount of carbon in the atmosphere is . . .

    decreasing with the recent use of alternative alternative fuels.

    staying about the same.

    increasing at a steady pace.

    increasing at an increasing pace.

  19. Sulfur dioxide reacts with water vapor resulting in acid rain. Which reaction below correctly illustrates this reaction?

    SO2 + H2O H2SO3

    SO2 + H2O HSO2 + OH -1

    SO2 + H2O SO + 2 OH -1

    None of these are correct.

  20. Nitrogen oxides, NOX, are produced primarily from which of the sources below?

    Stationary Sources (Power Plants)

    Mobile Sources (Internal Combustion Engines)

    Industrial Processes (Manufacturing)

    None of the above.

  21. Which reaction below shows a neutralization reaction?

    H2CO3 + H2O H3O+1 + HCO3 -1

    NaOH Na +1 + OH -1

    HCl + NaOH H2O + NaCl

    None of these show a neutralization reaction.

  22. Milk has a pH = 6, it is therefore . . .

    Very Acidic

    Slightly Acidic

    Slightly Basic

    Very Basic

  23. Coca Cola has a pH = 3 and stomach fluid has a pH = 1. How many more times acidic is stomach acid than Coca Cola?

    2 x more acidic

    3 x more acidic

    100 x more acidic

    1000 x more acidic

    Diagrams of Acids are Shown Below. Use the Diagrams to Answer Questions 25 and 26.

    I.

    II.

    III.

  24. Which of the acids shown is the most concentrated?

    I only

    II only

    III only

    II and III only

  25. Which acid is a weak acid?

    I only

    II only

    III only

    I and III only

  26. The units for concentration are moles solute per liter of solvent (molarity - M). A 2.0 M solution has a volume of 3.0 L. How many moles of solute are there in the solution?

    6 moles

    1.5 moles

    0.67 moles

    None of the above are correct?

  27. A buffer solution . . .

    is an acid.

    is a base.

    is neutral.

    resists changes in pH.

  28. Volatile organic chemicals (VOCs) are primary air pollutants. The major source of VOCs is _______.

    Transportation

    Industrial Processes

    Agriculture

    Forest Fires

  29. Temperature inversions often contribute to poor air quality in the Willamette Valley during the summer. A temperature inversion . . .

    occurs when cool, dense air is trapped beneath less dense, warm air.

    often occurs in valleys close to the ocean that are bounded by mountains.

    tends to trap air pollutants so they build up in a certain location over a period of days.

    A, B, and C are all correct.

  30. Which strategies below are useful in controlling and preventing air pollution?

    I. Developing New Technologies That Do Not Rely on Combustion
    II Conserving Energy
    III. Remove Pollutants Before, During, or After Burning
    IV. Finding Alternative Sources of Fossil Fuels

    I only

    I and II only

    I, II, and III only

    I, II, III, and IV only

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