Question

A student performs a reaction twice. In the second trial, he increases the temperature of the reaction and notes that the reaction happens more quickly. The student concludes that this means the reaction was endothermic. What is wrong with the student's reasoning?

Higher temperature increases reaction rates for both endothermic and exothermic reactions.

An endothermic reaction would not speed up at higher temperatures.

Temperature does not affect the rate of a reaction.

The higher temperature in the second trial actually lowered the activation energy of the reaction.