Chapter 4: Climate Change
These questions cover Chapter 4 – all sections

Total point value for this assignment = 30 pts

1. Consider these three types of radiant energy, all emitted by the Sun: infrared (IR), ultraviolet (UV), and visible. (1 pts)

a. Arrange them in order of increasing wavelength.

b. Arrange them in order of increasing energy.

2. The chapter concluded with a quote from John Holdren: “Global warming is a misnomer, because it implies something that is gradual, something that is uniform, something that is quite possibly benign. What we are experiencing with climate change is none of those things.”

Use examples to: (3pts)

a. explain why climate change is not uniform

b. explain why it is not gradual, at least in comparison to how quickly social and environmental systems can adjust.

c. explain why it probably will not be benign

3. Using the strategies found in Chapter 4, draw the Lewis structure and name the geometry for each molecule. (5 pts)

a. H2S

b. SO2 (Sulfur is the central atom) Hint: because S and O are in the same group on the periodic table, the structures for sulfur dioxide and ozone will be closely related

c. N2O (nitrogen is the central atom)

d. PF3

e. HCN (carbon is the central atom)

f. CF2Cl2 (carbon is the central atom)

4. Using the diagram below, answer these questions (2pts)

a. eub2297x_0320.jpgWhich processes add carbon (in the form of CO2 ) to the atmosphere?

b. Which processes remove carbon from the atmosphere?

c. What are the two largest reservoirs of carbon?

d. Which parts of the carbon cycle are most influenced by human activities?

5. Nitrogen (N) is an important element in the atmosphere and in biological systems. It has two naturally occurring isotopes: N– 14 and N– 15. (2pts)

a. Use the periodic table to find the atomic number and atomic mass of nitrogen.

b. What is the number of protons, neutrons, and electrons in a neutral atom of N– 14?

c. Compare your answers for part b with those for a neutral atom of N– 15.

d. Given the average atomic mass of nitrogen, which isotope has the greatest natural abundance?

6. Explain each of these observations. (2pts)

a. A car parked in a sunny location may become hot enough to endanger the lives of pets or small children left in it.

b. Clear winter nights tend to be colder than cloudy ones.

c. A desert shows much wider daily temperature variation than a moist environment.

7. Water vapor and carbon dioxide are greenhouse gases, but N2 and O2 are not. Explain. (2pt)

acs48763_pr0316 8. Three different modes of vibration of a water molecule are shown. Which of these modes of vibration contributes to the greenhouse effect? Explain. (2pt)

9. Silver has an atomic number of 47. (2pt)

a. Give the number of protons, neutrons, and electrons in a neutral atom of the most common isotope, Ag-107.

b. How do the numbers of protons, neutrons, and electrons in a neutral atom of Ag-109 compare with those of Ag-107?

10. Termites possess enzymes that allow them to break down cellulose into glucose, C6H12O6, and then metabolize the glucose into CO2 and CH4.

a. Write a balanced equation for the metabolism of glucose into CO2 and CH4. (look in your text) (1pt)

b. What mass of CO2, in grams, could one termite produce in one year if it metabolized 1.0 mg glucose in one day? (1pt)

11. Calculate the molar mass of each of these compounds. Each plays a role in atmospheric chemistry. (3pt)

a. N2O

= (2 x molar mass of N) + (1 x molar mass of O)

= 2 x (14 g / mol) + 1 x (16 g / mol)

= 44 g / mol

b. CCl3F (Freon-11)

c. CH4

12. a. Calculate the mass percent of chlorine in CCl3F (Freon-11). (2pts)

b. What is the maximum mass of chlorine that could be released in the stratosphere by 100 g of Freon-11?

c. How many moles of atomic chlorine (Cl) correspond to the mass calculated in part b?

d. How many atoms of chlorine (Cl) correspond to the mass calculated in part b?

13. A solar oven is a low tech low cost device for focusing sunlight to cook food. How might solar ovens help mitigate global warming? Which regions of the world would benefit most from using this technology? (2pts)