[LHM]

For an exothermic reaction in which 2 mol of gaseous reactants are converted to 3 mol of gaseous products, which will lower the reaction rate?
A) decreasing the volume
B) decreasing the temperature

It says that decreasing the temperature lowers the reaction rate, but I don't see what this would be true. Since it's exothermic, wouldn't decreasing the temperature cause more products to be formed? And since there are less moles of gaseous reactants, why wouldn't decreasing the volume lower the reaction rate?

[Fluorine]

I might be incorrect but, concentrations are a important aspect of reaction rate however temperature (energy) is fundamental. In this image both endothermic and exothermic reactions require an activation energy to complete the reaction. Just because a reaction is exothermic does not mean it does not need a "start up" energy.

[rabolisk]

Lowering temperature almost always decreases the reaction rate. Lowering volume does not mean that the amount of reactants will be lowered. It actually means (for gases) that the concentration would increase, so the rate would increase.

Don't confuse kinetics and thermodynamics.

[LHM]

So this doesn't have anything to do le chatelier's principle theorem then because this isn't at equilibrium?

[rabolisk]

Le Chatelier's principle has nothing to do with kinetics.