For the following reaction
$$\ce{W(s) + 4 Br(g) <=> WBr4(g)}$$
at $\pu{900 K},$ $K_p = 100$ and at $\pu{2800 K}$, $K_\mathrm{p} = 5.$
Determine if the reaction is endothermic or exothermic.
At higher temperatures, the equilibrium has shifted towards the reactants since $K_p$ is significantly smaller. However, how do we determine if a reaction is endothermic or exothermic from this information?
If the reaction was endothermic, an increase in temperature would push the equilibrium to products to counteract the increase in heat. However, the equilibrium has been pushed to the reactants thus signifying the reaction is exothermic. But this assertion is on the assumption that the forward reaction is exothermic.