Find out whether the rate of reaction changes with certain types of effects, such as temperature and concentration.

Authors Avatar

Mohamed Sudi

11Y4

Rate of Reaction Coursework

Aim:

        My aim for this experiment is to find out whether the rate of reaction changes with certain types of effects, such as temperature and concentration.

Prediction:

        Through my preliminary experiment I predict that in this experiment, where the temperature is varied, the rate of reaction will increase as the temperature increases. This can be identified by relating to the collision theory.

As you can see from the picture below, in the first box the particles of both, the Hydrochloric acid and Thiosulphate, move continuously. In the second box you can see that they have reacted, mainly because there was enough energy to provide a collision. However the third box shows the results of what may happen that there would be no reaction if there were no energy from the particles.

        When the temperature is increased, the particles will have more energy and therefore move faster. This means that there is more possibility that they’ll collide more often and with more energy. Particles with more energy are more likely to overcome the activation energy barrier to reaction and therefore react successfully.

        In order for particles to react with one another, they must collide with each other and the collision must have energy.

        To successfully complete my experiment I will vary the temperature by simply using the water tube to increase or decrease the temperature by adding more cold water or more hot water.

Scientific Knowledge:

        The reason for my prediction is that when the temperature is increased the rate of reaction will also increase. This is mainly because the molecules will collide more often and with greater energy and will be more likely to react because their bonds will break. I know this fact through my understanding of the collision theory.

I also know that Sodium Thiosulphate and Hydrochloric acid are soluble in water, so the concentration of either can be changed. However I have chosen to keep the sodium Thiosulphate constant and only vary the temperature, as that is the first part of my experiment (to investigate temperature).

As I have mentioned in my prediction, when the temperature is being varied I will use a water bath in a tube to heat up the acid and Thiosulphate to the necessary temperatures.

A reaction would be impossible to obtain, unless the particles collide with a certain minimum energy called the ‘activation energy’ of the reaction. Activation energy is the minimum energy required before a reaction can occur. You can show the reaction of this on a graph.

For a simple over-all exothermic reaction, the energy on a graph would look like this:

        If the particles collide with less energy than the activation energy, nothing important happens. They bounce apart. You can think of the activation energy as a barrier to the reaction. Only those collisions that have energies equal to or greater than the activation energy result in a reaction.

        Any chemical reaction results in the breaking of some bonds, which needs energy, and the making of new ones, which releases energy. The releasing of energy is known as endothermic and the need of energy is called exothermic. Obviously some bonds have to be broken before new ones can be made. Activation energy is involved in breaking some of the original bonds. At this moment the collisions are gentle, because there isn't enough energy available to start the bond-breaking process, and due to this the particles don't react.

        From this I am able to say that particles that react with substances at low temperature do not need much energy. However when the substance is heated, in this case the Hydrochloric acid and the Thiosulphate, this causes them to collide more often. The fact that the collision has more energy makes it successful; therefore the rate of reaction will increase.

        I also know that only a small percent result in a reaction and this is due to the energy barriers, and particles with enough energy are only able to break through the barrier.

        Also the size of this activation energy is different for different types of reactions. If the rate of collisions is increased the rate of reaction will also increase.

Join now!

        An increase in the rate of collision or the rate of reaction can be achieved by increasing the concentration, pressure, or surface area

List of Apparatus:

  • 2 Beakers,
  • 1 measuring cylinder,
  • 2 Boiling tubes,
  • Paper with ‘X marks the spot’,
  • Hydrochloric acid,
  • Thiosulphate,
  • Stopwatch,
  • Spatula,
  • Conical flask,
  • Thermometer,

Method:

These are the steps, and the reasons, in which I will take in order to complete my experiment and to get my preliminary results:

  1. To begin with I will set my equipment that will help me accomplish my results. The equipments ...

This is a preview of the whole essay