a) Using only the following information:

• ∆H°f for NO (g) is +90.4 kJ/mol

• ∆H° = -56.6 kJ/mol for the reaction: NO (g) + 1/2 O2 (g) à NO2 (g) What is the ∆H°f for NO2 (g).

b) Using only your answer to (a) and the following information:

•∆H° = -283.0 kJ/mol for the reaction: CO (g) + 1/2 O2 (g) à CO2 (g)

What is the ∆H° for the reaction: 4 CO (g) + 2 NO2 (g) à 4 CO2 (g) + N2 (g)

c) A 10.0-L vessel contains 5.0 atm of CO and 3.0 atm of NO2 at 25°C. How much heat (in Joules) will

be liberated if this is allowed to react to completion according to the reaction in part (b)?

d) In a separate experiment using a very large reaction vessel with a movable piston, 6.00 moles of CO2 (g) reacts completely with 3.00 moles of nitrogen gas according to the following equation at 25°C and with a constant external pressure of 2.00 atm:

4CO2 (g) + N2 (g) –> 4CO(g) + 2NO2 (g)

This reaction proceeds to completion. What is ∆U, q, and w for this reaction under these conditions.