Chapter 14, Problem 14.119QP

Consider the reaction ${\text{N}}_2{\text{O}}_4(g)\stackrel{}{\rightleftharpoons }{\text{2NO}}_2(g)$. Would you expect this reaction to be endothermic or exothermic? Why? N₂O₄ is a colorless gas; NO₂ is red-brown. Would you expect a mixture of these gases to become more or less red-brown as you raise the temperature? Explain.