hich of the following changes always leads to an increase in the rate constant for a reaction: Decreasing the temperature Decreasing the activation energy Making the value of ΔEΔE more negative Only one—(i), or (ii), or (iii)—increases the reaction rate. (i) and (ii) (i) and (iii) (ii) and (iii) All three—(i), (ii), and (iii)—increase the reaction rate.