Brown nitrogen dioxide combines to produce colourless dinitrogen tetroxide in a reversible reaction. The forward reaction is exothermic. $\text{2NO}_2(\text{g}) \rightleftharpoons \text{N}_2\text{O}_4(\text{g})$ Which changes would cause the equilibrium mixture to become darker in colour?
- Atemperature decrease, pressure decrease
- Btemperature decrease, pressure increase
- Ctemperature increase, pressure decrease
- Dtemperature increase, pressure increase