1.(A) Calculate the density of NO2 gas at 0.970 atm and 35 degrees Celsius.

(B) Calculate the molar mass of a gas if 2.50 grams occupies 0.0875 liters at 685 torr and 35 degrees Celsius.

2. What molecular features make a polymer flexible? Explain how cross linking affects the chemical and physical properties of the polymer.

3.(A) What is an ideal solution?

(B) The vapor pressure of pure water at 60 degrees Celsius is 149 torr. The vapor pressure of water over a solution at 600 degrees Celsius containing equal numbers of moles of water and ethylene glycol (a nonvolatile solute) is 67 torr. Is the solution idea according to Raoult's law? Explain.

4. The isomerization of methyl isonitrile (CH3NC) to acetonitrile (CH3CN) was studied in the gas phase at 2150 degrees Celsius, and the following data was obtained:

Time (in seconds) - [CH3NC] (M)
0s - 0.0165
2000s - 0.0110
5000s - 0.00591
8000s - 0.00314
12000s - 0.00137
15000s - 0.00074

(A) Calculate the average rate of reactions, in M/s, for the time interval between each measurement.

(B) Graph [CH3NC] vs time, and determine the instantaneous rates in M/s at t=5000s and t=8000s.

5. The equilibrium constant for the reaction 2NO(g) + Br2(g) <--> 2 NOBr(g) is
Kc = 1.3 X 10^-2 at 1000K.

(A) Calculate Kc for 2NOBr(g) <--> 2NO(g) + Br2(g)

(B) At this temperature does the equilibrium favor NO and BR2 or does it favor NOBr?

6. Which of the following cations will be the most acidic and why: Ca2+, Fe2+, Fe3+

7. A 1.00L solution saturated at 25 degrees Celsius with calcium oxalate (CaC2O4) contains 0.0061 grams of CaC2O4. Calculate the solubility product constant for this salt at 25 degrees Celsius.

8. The complexes [V(H2O)6]3+ and [VF6]3- are both known.

(A) draw the d-orbital energy level diagram for V(III) octahedral complexes.

(B) what gives rise to the color of the complexes?

(C) Which of the two complexes would you expect to absorb light of higher energy? Explain.