1. Which of the following compounds would have the highest boiling point?
2. The monomers below would react with each other and form:
a. A polycarbonate
b. A polyamide
c. A polyester
Draw the polymer
What kind of polymer is this?
3. A liquid is observed to have a high surface tension. What can you predict about its vapor pressure and boiling point?
4. If there is 1.00 mol of pure NO2 in a 40.0 liter container and we allowed it to react per the reaction listed below at 150°C. At equilibrium, the concetration of NO in the container is found to be 0.0015 M. Use that information to calucalte the equilibrium constant for the following reaction.
2NO2 (g) ↔ 2NO (g) = O2 (g)
5. The conductivity of semiconductors increases with increase in temperature. Using band theory, explain this observation.
6. What is the packing efficiency of a face center cubic? Please explain using mathematical equations and/or drawn figures?
7. What is the molar solubility of lead(II) phosphate in a 0.282 M sodium phosphate solution?
8. Calculate the concentration of the hydronium ion H3O+ in a solution that has a pOH of 3.15
9. Using the table on the preceding page
a. Write the reaction for the dimethylammonium ion acting as an acid when it is added to water.
b. Calculate the pH of a 0.20 M solution of dimethylammonium hydrochloride.
c. Write the reaction for propylamine acting as a base when it is added to water
d. Calculate the pH of a 0.10 M propylamine solution.
e. Write the reaction for cyanide ion, CN-, acting as a base when it is added to water
f. Calculate the equilibrium pH of a solution that has an initial concentration of 0.20 M sodium cyanide.
10. Consider the follow reaction:
2SO2(g) + O2(g) 2SO3(g)
A chemist places 0.0040 mol of SO2(g) and 0.0028 mol of O2(g) in a 0.50 liter container at a particular temperature. When the reaction comes to equilibrium he determines that there are 0.0015 moles of SO3(g) that have been formed. Use this information to calculate the equilibrium constant for this reaction.
11. Shown below are three possible forms of a thermoplastic polymer. Which of these three form would you expect to become soft and moldable at the lowest temperature? Or would you expect all three forms of the polymer to be soft and moldable at the same temperature? Briefly explain.
12. Is it possible to make an n-type semiconductor from Germanium? If so, how would you do this? Explain. Your explanation should begin by describing what an n-type semiconductor is.
13. Identify the kinds of intermolecular forces (dispersion, permanent dipole-permanent dipole that is not hydrogen bonding, or hydrogen bonding) that are most important in each of the following substances.
a. nitric oxide (NO)
b. methylamine (CH3NH2)
c. chloroform (CHCl3)
d. posphine (PH3)
14. Which type of material has the smallest bandgap?
d. Not enough information to tell.
15. Predict whether the hydrogen bonding between –OH bonds will be stronger or weaker than the hydrogen bonding between –NH bonds. Briefly explain.
16. Copper crystallizes into a face centered cubic lattice. It has a density of 8.97 g/cm3. Use this information to calculate the size of the unit cell for this crystal lattice.
17. ABS is a mixed polymer that is used to make canoes. It is a material that can take an impact without breaking. “A”, “B” and “S” stand for the three polymers that are combined in ABS. For any one of these three, identify what the polymer is, identify one practical application of this polymer and indicate how this particular polymer contributes to the overall properties of the can
18. Explain why Teflon does stick to anything. Teflon is a polymer with the structure shown below.
19. Draw the structure of the condensation polymer that forms from the following two comonomers:
20. Consider the reaction, 2A B + C. You start with 1.0 M A and no B or C. The graph below shows how the concentration of product B changes with time. On this graph, draw how the concentration of reactant A would change with time as the reaction comes to equilibrium.
21. Consider the following reaction that is occurring inside a sealed container:
CH4(g) + NH3(g) HCN(g) + 3H2(g)
If we increase the volume of the sealed container without changing the temperature, will this affect the amounts of product and reactant in this container? If so, will the amounts of products increase or decrease. Briefly EXPLAIN!
22. Mustard gas, S(CH2CH2Cl)2 can be prepared by reacting sulfur dichloride, SCl2, with ethylene, C2H4:
SCl2(g) + 2C2H4(g) S(CH2CH2Cl)2
If we start with 0.675 M SCl2(g) and 0.973 M C2H4(g) at 20 oC and allow them to react, the equilibrium concentration of S(CH2CH2Cl)2(g) is 0.350. Calculate Kc for this reaction from these data.
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