Le Chatelier's Principle; Temperature

Question

Given the following reaction:

N2O4(g)

<-->

2 NO2(g)

colorless red

If the temperature of the reaction is decreased, the mixture becomes colorless indicating that the reaction is

A. Endothermic

B. Exothermic

Answer 1

Endothermic

In an endothermic reaction, heat is on the reactant side of the equation. If that heat is removed, the reaction will shift to the left to create more reactants and restore equilibrium.