Investigating Factors that Affect the Rate of Reaction

Investigating Factors that Affect the Rate of Reaction

There are certain factors which affect the rates of reaction in an

experiment. These factors are:

· Pressure

· Temperature

· Concentration

* Surface area / particle size and

* The addition of a catalyst

The factors that I will be concentrating on are temperature,

concentration and surface area / particle size.

Pressure

Pressure influences the rate of reaction only when the reactants are

in their gas phase. Pressure does not affect them much when they are

either solids or liquids. By increasing the pressure, you squeeze the

molecules together so you will increase the frequency of collisions

between them and their surrounding container.

Temperature

When the temperature of a reaction increases, heat is supplied to the

particles of the reactants involved. This heat energy is converted

into kinetic energy which all of the particles acquire. This means

that more particles collide with each other per second. In addition,

the faster the particles are travelling, the greater proportion of

them which will have the required minimum energy for reaction to

occur, for example, raising the temperature of a reaction by 10°c will

double the rate of the reaction.

Concentration

A chemical reaction will occur only if the particles of the reacting

substances are allowed to come into contact. This is based on the

kinetic theory:

The rate of reaction would be expected to depend on the frequency with

which the particles collide, which in turn will depend (among other

factors) on their density, i.e. on their concentration. The more

crowded the particles are, the more often we should expect them to

bump into each other.

Surface Area

A solid in a solution can only react when particles collide with the

surface. The bigger the area of the solid surface, the more particles

can collide with it per second, and the faster the reaction rate is.

You can increase the surface area of a solid by breaking it up into