Which statement is true regarding reaction rates? A.

Temperature does not affect the reaction rate.

B.

Increasing temperature or adding a catalyst will decrease the reaction rate.

C.

Increasing temperature or adding a catalyst will increase the reaction rate.

D.

Decreasing temperature and adding a catalyst will increase the reaction rate.

E.

A catalyst does not affect the reaction rate.

THE TRUE STATEMENTS REGARDING REACTION RATE IS "INCREASING TEMPERATURE OR ADDING A CATALYST WILL INCREASE THE REACTION RATE".

Explanation:

The rate of a chemical reaction is the number of moles of reactant converted or product formed per unit time. There are various factors that affect reaction rate and they include;

1. Nature of the reactant

2. concentration and pressure of reactants. pressure is for gases.

3. temperature of the reactants.

4. surface areas of the reactants

5. presence of light

6. presence of catalyst.

I will talk about the role of temperature and catalyst in reaction rate.

TEMPERATURE:

The rate of virtually all reactions (chemical) increase when the temperature is increased. increasing the temperature of a system both exothermic and endothermic reactions, energy in the form of heat is supplied to the system which thus increases the number of particles with energies equal to or more than the activation energy of the system. This increase in particles leads to increase in collision and thus the reaction proceed faster.

CATALYST

A catalyst is a substance which alters the rate of a chemical reaction but remains unchanged at the end of the reaction. Catalyst operates by providing an alternative route for the reaction to occur. So adding a catalyst and has a lower activation energy when added increases the rate of reaction as more particles can collide with each other. This kind of catalyst is called positive catalyst. A catalyst that provides an alternative route with a higher activation energy is called negative catalyst.