How Does Decreasing Temperature Affect SO3 Production in a Chemical Equilibrium?

[reyrey389]

What will happen to the number of moles of SO3 in equilibrium with SO2 and O2 in the reaction
2SO3(g) <-> 2SO2 (g) + O2 (g) H = 197kJ if the temperatrue is decreased?

I know this is endothermic, so heat is on the reactant side and that the reaction will shift to the left, so SO3 increases?

 

[tex43]

Le Chateliers Principle states that any dynamic equilibruim will oppose changes imposed. Therefore heating an endothermic reaction will force the equilibrium in the endothermic direction which in your example would be to the right

 

[Borek]

Le Chateliers Principle states that any dynamic equilibruim will oppose changes imposed. Therefore heating an endothermic reaction will force the equilibrium in the endothermic direction which in your example would be to the right

(bolding mine)

According to the original question temperature is decreasing. That means mixture was cooled, not heated.

 

[tex43]

Apologies Borek, didn't read the question properly ... cardinal sin.

 

[LudusRex]

Le Chatalier's Principle states that when a system at equilibrium is subjected to a change, the system will respond in a way that minimizes the effect of that change. In this case, since the temperature is decreased, the reaction is shifted to the left in order to consume more heat and maintain equilibrium. This means that the number of moles of SO3 will increase, as it is the reactant in the forward reaction. This is in accordance with the principle, as increasing the amount of SO3 will consume more heat and shift the reaction back to equilibrium. Therefore, the number of moles of SO3 will increase in this scenario.