Question

For which of the following reactions will an increase in temperature shift the equilibrium to the left?
(Points : 3)

A + B arrow AB; ΔH = +23 kJ


A + B + heat arrow AB


AB arrow A + B; ΔH = −23 kJ


AB + heat arrow A + B

Answer 1

I would guess the second one

Answer 2

In order for equilibrium to shift to the left, the equation must favor the reverse reaction.
If stress (such as heat) is added, it will favor the opposite side.

Answer 3

AB arrow A + B; ΔH = −23 kJ

Answer 4

Yes, if you rewrite it becomes AB -> A+B+heat

Since heat is added to the right, in order for balance to be restored the equilibrium must shift to the left.