Chemistry 30

For each of the follwoing equilibria, predict whether the system will shift in the forward or reverse directions. Note the energy changes involved and assume that the volume remains constant.

a.	heat is removed from: A B	ΔH° = +40.0 kJ
b.	heat is removed from: A + B 2 C	ΔH° = -25.5 kJ
c.	heat is added to: A + 2B 3 C	ΔH° = -32.0 kJ

You will likely find it easier to answer the question if you first rewrite each equation by including the energy term as part of the equation.

In each of the following equilibria, would you increase or decrease the temperature to force the reaction in the forward direction?

a.	H2 (g) + CO2 (g) H2O(g) + CO(g)	ΔH° = +41.0 kJ
b.	2 SO2 (g) + O2 (g) 2 SO3 (g)	ΔH° = -198 kJ

For each of the equilibria in Question 2 will the value for K_eq increase or decrease if the temperature is raised?

Explain the effect of using a platinum catalyst in the equilibrium reaction of ammonia with oxygen:

4 NH_{3 (g)} + 5 O_{2 (g)} 4 NO_(g) + 6 H₂O_(g) + heat