Changes in temperature also affect equilibrium. To predict this effect, heat may be considered as a
product in reactions that release energy (exothermic reactions), and as a reactant in reactions that
absorb energy (endothermic reactions). Consider the following exothermic reaction:
A → B + heatBASIC CONCEPT
If this system were placed in an ice bath, its temperature would decrease, driving the reaction to the
right to produce more heat. Conversely, if the system were placed in a boiling-water bath, the
reaction equilibrium would shift to the left because of the increased “concentration” of heat.
Not only does a temperature change alter the position of the equilibrium, it also alters the
numerical value of the equilibrium constant. In contrast, changes in the concentration of a species
in the reaction will alter the position of the equilibrium without changing the numerical value of the
equilibrium constant.
Higher temperature: favors reactant if exothermic (heat as product)
Lower temperature: favors product if exothermic