How do catalysts increase the rate of reaction

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. Learning Objective Explain how concentration, surface area, pressure, temperature, and the addition of catalysts affect reaction rate. Key Points When the concentrations of the reactants are raised, the reaction proceeds more quickly.

This is due to an increase in the number of molecules that have the minimum required energy. For gases, increasing pressure has the same effect as increasing concentration. When solids and liquids react, increasing the surface area of the solid will increase the reaction rate. This is due to an increase in the number of particles that have the minimum energy required.

The diagram shows that a catalyst provided a reaction pathway of lower activation energy. This makes more of the collisions successful at a given temperature.

Prescribed Practical C6 - Investigate how changing a variable changes the rate of reaction. Effect of catalysts The rate of a reaction can be increased by adding a suitable catalyst. Enzymes are important for controlling reactions in cells. They are also important in industry. The use of enzymes allows some industrial reactions to happen at lower temperatures and pressures than traditionally needed. Yeast is a single-celled fungus. The enzymes in yeast are used to produce wine, beer and other alcoholic drinks by fermentation of sugars.

Catalysts A catalyst is a substance that: increases the rate of a reaction does not alter the products of the reaction is unchanged chemically and in mass at the end of the reaction Only a very small mass of catalyst is needed to increase the rate of a reaction. Catalyst Reaction catalysed Iron Haber process making ammonia Vanadium V oxide Contact process a stage in making sulfuric acid Manganese dioxide Decomposition of hydrogen peroxide produces water and oxygen Notice that these catalysts are transition metals or compounds of transition metals.

How catalysts work A catalyst provides an alternative reaction pathway that has a lower activation energy than the uncatalysed reaction. A reaction profile for a reaction with and without a catalyst Enzymes An enzyme is a biological catalyst.