Question

which will increase the rate of a chemical reaction? adding a catalyst decreasing the pressure decreasing the temperature removing a catalyst

Explanation:

A catalyst lowers the activation - energy of a chemical reaction, allowing more reactant molecules to have enough energy to react and thus increasing the reaction rate. Decreasing temperature reduces the kinetic energy of reactant molecules and slows down the reaction. Decreasing pressure (for reactions involving gases) reduces the frequency of collisions between reactant molecules and decreases the reaction rate. Removing a catalyst will not increase the rate as the catalyst is what speeds up the reaction.

Answer:

adding a catalyst