chemistry homework

1) CFCs were used in hair sprays, refrigerators, air conditioners, and plastic foams. Which properties of CFCs made them desirable for these uses?

2) a. Can a molecule that contains hydrogen be classified as a CFC?

b. What is the difference between an HCFC and an HFC?

3) Give names and chemical formulas for five acids of your choice.

4) Write a chemical equation that shows the release of one hydrogen ion from a molecule of each of these acids.

a. HBr(aq), hydrobromic acid

b. HC2H3O2(aq), acetic acid

5) Give the names and chemical formulas for five bases of your choice.

6) Write a chemical equation that shows the release of hydroxide ions as each of these bases dissolves in water.

a. Ba(OH)2(s), barium hydroxide

7) Write a balance chemical equation for each acid/base reaction.

a. Potassium hydroxide is neutralized by nitric acid.

b. Hydrochloric acid is neutralized by barium hydroxide.

c. Sulfuric acid is neutralized by ammonium hydroxide.

8) Classify these aqueous solutions as acidic, neutral, or basic.

a. HI(aq)

b. NaCl(aq)

c. NH4OH(aq)

d. [H+] = 1 X 10-8 M

e. [OH-] = 1 X 10-2 M

f. [H+] = 5 X 10-7 M

g. [OH-] = 1 X 10-12 M

9) For parts d and f of the previous question, calculate the [OH-] that corresponds to the given [H+]. Similarly, for parts e and g, calculate the [H+].

And answer the following questions related to CFCs and acid rain

1.  Where is the ozone hole?  List at least 3 factors, man-made and natural, that have contributed to the destruction of ozone.

 

2.  What are CFCs?  List a couple and their uses.  Why were they such an environmental problem?

 

3.  Consider This:  2.26a,b

 

4.  What has been done to reduce/eliminate the problem of CFCs?

 

5.  What compounds are responsible for acid rain?  Draw the chemical equations (reactions) that explains the decrease in pH.

 

6.  What has contributed to higher sulfur dioxide emissions?

 

7.  Which part of the US suffers more from lower pH rain?

 

8.  Discuss how coal has affected our environment.

 

9.  List at least 5 effects acid rain has on the environment/humans.

 

10.  Explain why the lakes and streams in the Midwest, an area of acidic precipitation, still remain healthy for aquatic life.  A chemical equation would be helpful here.