Chemistry - Collision Theory

.Experiment for Chemistry Coursework

For this investigation I am looking at how the concentration of acid can change the reaction and how I can explain this using collision theory.

My Prediction: I predict that the greater amount of concentration the faster the reaction will take place. Therefore, particles in the two compounds will collide faster. Due to my prediction if it is correct, I expect to see the cross on the paper disappear faster. As I already know that increasing one quantity will speed up the reaction as the particles are more likely to collide.

In this investigation several measures will need to be done to make sure that the results I get will be precise. From the planned

method I can work out what will need to be done to achieve the best results possible. I will also need to think about what other factors may vary my results to someone else’s and how this could be improved.

Equipment Needed:

· Beaker

· Test-tube

· Piece of paper with a cross on

· 25mlІ of Sodium Phiosulphate

· 5mlІ of Hydrochloric Acid

Factors about the equipment that may affect the results:

The amount of one particular quantity, or concentration of the acid. The type of acid that was used may either slow down or speed up the reaction. Also, another factor maybe that the time it take until I begin to start the stopwatch. To control the problem of affecting results I would have to swirl the mixture for e.g.: every 2 seconds. However, this would have to be done in every type of concentration and experiment.

Diagram of method:

Method: Draw a cross on a piece of paper and place a beaker on top of the paper. This is because once the cross disappears I know the reaction has completed as the compounds have now become one solution.

Secondly, measure as accurately as possible 25mlІ of Sodium Phiosulphate and 5mlІ of Hydrochloric acid.

Thirdly, pour the measured amount of Sodium Phiosulphate into the beaker and then add the Hydrochloric acid. Once this is added start the timer.

Finally, once the cross has completely disappeared stop the clock and make a not of the time it took for the mixture to become one.

NOTE: This procedure was produced with different concentrations. This was so that I could see whether the concentration had an affect on experiment’s time limit.

Results:

Before doing our experiment we saw a trail run on the computer known as:

MULTIMEDIA SCIENCE SCHOOLS

From the computers experiment I found results I would know what to expect when I would do my experiment. I learnt how different quantities and temperature can affect the speed of collision with in the particles.

From the experiment we had a set of results these were:

I looked at other groups results to see to see if their results corresponded to mine:

Limiting Factors:

The time it took till the clock was started and the difference between when “we” thought the cross was no longer visible.

Other Factors that may have affected our results:

The following may have affected our experiment in one way. This may have been the cause for any anomalous results. These included: The amount of hydrochloric acid measured incorrect, the amount of Sodium Phiosulphate measured incorrectly, size of the cross, any movement of the beaker, time taken until we began starting the stop clock.