Why does catalyst increased rates of reactions

The Effect of a Catalyst. Learning Objective Evaluate the effect of a catalyst on a chemical equilibrium. Key Points Catalysts are compounds that accelerate the rate of a reaction. Catalysts accelerate reactions by reducing the energy of the rate-limiting transition state. Catalysts do not affect the equilibrium state of a reaction. Show Sources Boundless vets and curates high-quality, openly licensed content from around the Internet.

Licenses and Attributions. CC licensed content, Shared previously. Similarly, the rate of reaction will decrease with a decrease in temperature. Catalysts are substances that increase reaction rate by lowering the activation energy needed for the reaction to occur. A catalyst is not destroyed or changed during a reaction, so it can be used again. For example, at ordinary conditions, H 2 and O 2 do not combine. However, they do combine in the presence of a small quantity of platinum, which acts as a catalyst, and the reaction then occurs rapidly.

Substances differ markedly in the rates at which they undergo chemical change. The differences in reactivity between reactions may be attributed to the different structures of the materials involved; for example, whether the substances are in solution or in the solid state matters. Another factor has to do with the relative bond strengths within the molecules of the reactants. For example, a reaction between molecules with atoms that are bonded by strong covalent bonds will take place at a slower rate than would a reaction between molecules with atoms that are bonded by weak covalent bonds.

This is due to the fact that it takes more energy to break the bonds of the strongly bonded molecules. Boundless vets and curates high-quality, openly licensed content from around the Internet.

This particular resource used the following sources:. Skip to main content. Chemical Kinetics. Search for:. Factors that Affect Reaction Rate. Activation energy is the minimum energy needed for a reaction to occur when two particles collide. It can be represented on an energy level diagram. We will look at this in more detail in unit 2. The diagram shows that a catalyst provided a reaction pathway of lower activation energy.