Question

ACTIVITY: EXPLORING FACTORS THAT AFFECT EQUILIBRIUM (CHECK ATTACHED IMAGE)

-As the temperature increased, what happened to the [N2O4]?
-Was the formation of reactants or products favored by the addition of heat?
-Which reaction is exothermic?
-If the change of enthalpy of this reaction when proceeding left to right is 14 kcal, which chemical equation is correct?

Answer 1

As temperature is increased, by Le Chatelier's Principle, in an endothermic reaction (forward direction), the equilibrium will shift to the right, the product side, thus increasing the 2NO2, and decreasing the N2O4, in an attempt to counteract the imposed change to the system. The reverse reaction is exothermic. As you can see in the diagram, when the test tube is placed in the beaker of hot water, the heat added makes the reddish brown colour characteristic of NO2 more concentrated, which indicates the equilibrium shifting to the right.

I'm not sure about the last one since I use joules (J) and kilojoules (kJ), not kcal.