HW

1. We live in an atmosphere of 21% oxygen. A match burns in less than a minute, a fireplace consumes a small pine log in about 20 minutes, and we exhale about 15 times a minute. Life on Earth would be very different if the oxygen concentration were half as high. (ie 10% instead of ~21%) (4 pts)

List at Two differences if the oxygen concentration on earth were at this reduced level what it currently is. (Assume that it is the nitrogen concentration that increased appropriately)

1).

2)

2. Calculate the volume of air in liters that you might inhale (and exhale) in a 24-hour day. Assume that each breath has a volume of about 0.5 L, and that you are breathing 15 times a minute. (if possible, show your calculation) (4pts)

3. From this calculation (above), you can see that breathing exposes you to large volumes of air. Identify 3 sources of particulate matter found in air (3pts)

1.

2.

3.

4. A carbon Monoxide detector will go off if the concentration of CO is 400ppm or greater for a period of 4-15 minutes. (4 pts)

a. Express 400 ppm as a percent

b. Why is carbon monoxide (CO) considered to be an air pollutant?

c. Is CO considered to be a primary or a secondary pollutant?

d. What is the major source of CO pollution in the air?

5. What is the troposphere, where is it found and why is it important? (2pts)

6. Give the names of these gases: (3pts)

CH4,

SO2

O3

7. Hydrocarbons are important fuels that we burn for many different reasons. (2pts)

a. What is a hydrocarbon?

b. Rank these hydrocarbons (from least to greatest) by the number of carbons they contain: propane, methane, butane, octane, and ethane.

8. Write balanced chemical equations to represent these reactions. (3 pts)

a. Nitrogen reacts with oxygen to form nitrogen monoxide.

Hint: Nitrogen and oxygen are both diatomic molecules. [O2 and N2]

b. Ozone decomposes into oxygen and atomic oxygen (O).

Hint: what is the chemical formula for ozone (check chapter 1)

c. Hydrogen gas burns in a reaction with oxygen to form water (dihydrogen monoxide) This is the reaction of the Hindenburg disaster.

Hint: Hydrogen and oxygen are both diatomic molecules. [O2 and H2]

11. A headline from the Anchorage Daily News in Alaska (January 17, 2008): “Family in car overcome by carbon monoxide. Fire department saves five after slide into snow bank? (3pts)

a. If your car is in the snow bank and the engine is running CO may accumulate inside your car. Normally, however, CO does not accumulate in the car, EXPLAIN why.