Short essay questions 8 points each due midnight, Thursday November 16, 2000
1.	Is the boiling process endo or exothermic? Why doesn't the temperature of a boiling liquid go higher than the boiling point temperature.

2.	What is the stronger intermolecular force, dipole-dipole or London forces? Why is there any difference?
	Give an example of a compound that has only London forces.

3.	Arrange the the following gases in order of increasing intermolecular forces. Identify the type of forces in each and say whether the forces are relatively strong or weak.
	HF, HBr, N2, He

4.

Nitrogen is used to fill a balloon at room temperature, 27 oC. The volume of the balloon is 3.0 L. The pressure inside and outside the balloon is 760 mm Hg. How many moles and grams of nitrogen are in the balloon? The universal gas constant is 0.0821 liter atm /mole Kelvin. Remember : PV = nRT Show work.

5.	Why is the vapor pressure for a liquid different at different temperatures? What is the definition for the normal boiling point? Can a liquid boil at a temperature other than the normal boiling point?

Multiple choice 2 points each max of 10 pts JUSTIFY CHOICE NO POINTS WITHOUT JUSTIFICATION

1.	Which of the following exhibits hydrogen bonding?
	a. H2
	b. CH3CH3
	c. CH3OCH3
	d. CH3CH2OH

2.	What is the volume of two mols of nitrogen at STP? a. need more data b. 22,400 mL c. 28 liters d. 44.8 L

3.	Which of the following has the highest melting and boiling point?
	a. CH3CH2CH2CH2CH3
	b. CH3CH2CH2CH3
	c. CH3CH2CH2CH2CH2CH2CH2CH2CH3
	d. CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH3

3.	What is the volume of 88 grams of CO2 at STP?
	a. 22.4 L
	b. 44.8 L
	c. 11.2 L
	d. need more data

4.	Which of the following molecules has the strongest London forces? Justify your choice. No credit for no justification.
	a. methane, CH4 b. hydrogen, H2 d. chlorine, Cl2 d. nitrogen, N2

5	There are 2 atoms "inside" the unit cell. How many atoms (consider their centers) needed to define the BCC unit cell
	a. nine b. four c. five d. eight