The Direction of a Reaction

The Direction of a Reaction Suppose we have a reaction such as A + B ↔ C , which has come to equilibrium at some temperature τ . Now we raise the temperature. Does the equilibrium shift to the left (more A and B) or to the right (more C)? The heat of reaction at constant pressure, Qp, is the heat that must be supplied to the system if the reaction goes from left to right. If Qp > 0, heat is absorbed and the reaction is called endothermic. If Qp < 0, heat is released and the reaction is called exothermic. For a reaction at constant pressure, the heat is the change in the enthalpy of the system, Qp = ∆H. We have H = G+ τσ , and σ = − (