adding a catalyst increases the rate of reaction. If the rate increases, then either k increases, or the order of the reaction changes. Explain which specific trials you might repeat with the catalyst in order to determine which is occurring.

The consistent trial is to vary rate constant with rate of reaction, since as the the rate of reaction increases, the rate constant also increases/decreases depending on which order of reaction is taken into consideration,

Explanation:

From the Arrhenius equation

k = Ae^ (-Ea/RT), generally as catalyst is added, the activation energy (Ea) decreases and since rate constant depends essentially on temperature and Rate of reaction on both temperature and concentration