Which of the following statements is false?
a. chemical reactions proceed more quickly at higher temperatures.
b. chemical reactions progress at a faster rate when the reacting particles are present in higher numbers. catalysts increase the rate of chemical reactions, sometimes while undergoing reversible changes in shape. larger particles move faster than smaller ones and thus collide more frequently and more forcefully.

Larger particles move faster than smaller ones and thus collide more frequently and more forcefully.

Explanation:

SMALER particles move faster than LARGER ones and thus collide more frequently and more forcefully.

The false statement is B.

Explanation:

When the temperature in a reaction increases, the rate of this reaction increases.

It means that it would be more probably to each molecule in the system collides but that does not mean that the reaction will happen faster because there is other factors that affect the velocity of the reaction, such as concentration of reactants, presence of catalyst, and activation energy.

Also, the nature itself of the reaction can affect the velocity, due to some of chemistry reactions occur instantaneously without increasing the temperature and in the case you increase the temperature the reaction will not occur quickly.

On the other hand, the size of the particle will affect the rate due to smaller particles are able to move faster than larger ones under high Temperature.