Investigation of the Rates of Reaction
By Gabriella Azanu 11A

Introduction

A chemical reaction is when a material is changed from a beginning mass to a resulting substance through the addition of one or more other substances. In a chemical reaction, at least one or more new substances are created and the beginning mass disappears in order to make the new mass. In a chemical reaction however, mass is neither lost nor gained so the resulting mass should still be the same as the beginning mass. A reaction can be perceived by either production of gas or a change in colour or properties.

A rate of reaction is the measurement of how quickly a reaction occurs. This can be done through following the formation of a product or the consumption of a reactant. This is turn can measured by observing colour changes or a precipitate forming.

There are four factors that can affect the rate of reaction, these are: the concentration, temperature, surface area and catalysts. The factors can be attributed to the collision theory and then each factor explained in more depth. In a reaction, molecules in substances can only react only if they collide into each other. The collision theory therefore states that as molecules collide, bonds between atoms can break whiles new ones form. This in turn creates new molecules. Because molecules are always moving in liquids and gases, there are millions of collisions between them every second. Very little of these collisions are successful and actually result in a reaction, as if all the collisions were successful then many reactions would be explosive. The successful reactions happen when molecules are moving with enough energy to break the bonds between atoms. Concentration, temperature, surface area and catalysts are factors that can be attributed to increasing the number of collisions