We can apply Le Chatelier's Principle to help us predict the effect of changing temperature on an equilibrium. The conversation below illustrates how we can do this.

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Think about the effect of heating the following equilibrium mixture:

H₂(g) + I₂(g) _∏ 2HI(g): ΔH_ʅ = –9.6 kJ mol^–1

How will the equilibrium mixture compare to its original composition when the equilibrium is re-established at a higher temperature?

The equilbrium mixture will contain more H₂(g) and I₂(g) and less HI(g).

How will the new value of K_p at the higher temperature compare to its original value?

The value of K_p will be lower.