Me i beg you i really need - check. you can study reaction rates to answer which of the following questions? will the reaction go to completion? will the reaction occur? how can the reaction be slowed down? how many grams of product will be made? changing the concentration of one or more of reactants can affect the rate of a reaction. false which of the following would increase the rate of a chemical reaction? reducing the temperature increasing volume using reactants in fine, powder form, rather than large, chunky decreasing reactant concentration a catalyst works by increasing the activation energy needed for a reaction. false

Changing the concentration of one or more of the reactants can affect the rate of a reaction. This is TRUE, as it means there are more collisions between particles and therefore a higher probability of successful collisions, which speeds the reaction up.
Using the reactants in a fine, powder form rather than a large, chunky form will increase the rate of a chemical reaction as the surface area of the reactants will increase. Therefore, there is a higher probability of successful collisions, which speeds the reaction up.
A catalyst works by increasing the activation energy needed for a reaction. This is TRUE, and the catalyst itself is not used up.
Sorry I couldn't get back to you earlier. I usually use the app so am unable to check comments on my wall. 

Answer is (d)a brainliest would be appreciated