Potentially useful information:
Avogadro's number = 6.02 x 10 ^23
1 bmt = 1 x 10 ^9 metric
tons
1 metric ton = 1 x 10 ^3 kilograms
1 kilogram = 1 x 10 ^3 grams
1 kilogram = 2.2 pounds
1 mole of gas = 22.4 liters (under standard conditions)
1. (5 pts) How many grams in 0.46 pound? Use the
appropriate number of significant figures.
What if the conversion factor given above said 1 kilogram = 2.2046 pounds?
2. (5 pts) Uranium-235 is the isotope that undergoes fission.
The atomic number for uranium is 92 - identify
the number of protons, neutrons, and electrons in one atom of U-235.
3. (5 pts) How many atoms of oxygen are in a mole
of CO2 ?
4. (5 pts) A carbon atom has how many total electrons?
How many valence electrons?
How does it typically satisfy the octet rule?
5. (5 pts) Write a Lewis electron dot structure for any CFC.
Show all valence electrons for all atoms.
6. (10 pts) The earth's carbon cycle appears to be out of balance by about 3 bmt of carbon per year.
How many moles is that?
If the excess is all CO2, how many bmt of CO2 is that?
7. (10 pts) What is a greenhouse gas and how does it contribute to global warming?
Explain what happens at the level of molecules
as well as at the level of the earth's energy balance.
8. (15 pts) Write a balanced equation for the combustion
of butane (C4 H
10 ).
A typical butane lighter might contain 1 mole of butane. How many grams
is that?
How much CO2 is
produced from the complete combustion of 1 mole of butane?
Express your answer in moles, grams, and liters.
9. (10 pts) Write a series of reactions that show
how ozone can be created in the upper atmosphere (just created - we don't
need the whole Chapman cycle).
Write a chain reaction that destroys ozone.
You may start with any compound you like to start the chain reaction.
Clearly show why this is called a chain reaction.
10. (15 pts) Given the information that one mole of a gas occupies a volume of 22.4 liters at standard atmospheric pressure, use the grid below to draw an approximate graph of what you would expect for the volume of one mole if you applied successively higher pressures of 2, 3, 4, and 5 atmospheres.
Label your axes. Can you write an equation relating pressure and volume?
11. (15 pts) Explain how you might decide whether NO2 or SO2 poses a greater health risk.
Indicate what data you would need and any assumptions you would make.