Rates of Reaction - Sodium Thiosulphate and Hydrochloric acid

Rates of Reaction - Sodium Thiosulphate and Hydrochloric acid

In this piece of coursework, I will study how concentration affects the rate of reaction. I will do so by timing the reaction of Sodium
Thiosulphate with an acid. In this coursework, I will include background knowledge, prediction, safety, results, calculations, graphs, an analysis, conclusion and an evaluation. In my evaluation I will comment on how reliable my results were and how I could have improved my coursework in any possible way.

The definition of rate of reaction is ‘The speed at which a chemical reaction takes place’. The factors that affect the rate of reaction are: · Use of a catalyst
· Temperature
· Surface area
· Concentration

I will be investigating Concentration in this experiment. In a higher concentration there are more Sodium Thiosulphate particles. This means there is a higher number of collisions which will have enough energy to react. This causes the rate to increase. The time it takes for a change to take place can be measured and can be estimated. For a reaction to take place 2 reactants must collide and the collision must have enough energy.

Prediction

I predict that as the concentration of the Sodium Thiosulphate increases the rate of reaction will increase. This can be proved by relating to the collision theory. I predict that as concentration is increased the amount of time taken for the reaction is halved.

Safety Issues

There are many safety issues that need to be considered while doing this experiment. These include:

· Wearing safety goggles at all times. If acids or any other chemicals are spilt, they would cause serious damage to the skin and eyes.
· Ties and long hair should be kept away from the experiment.
· If an accident ...

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... my evidence of this experiment is reliable because I did it with precision and carried it out carefully. I thought that I might have some anomalies but there were not any. I can prove this by using my prediction earlier in the experiment. I said that “as concentration is increased the amount of time taken for the reaction is halved.” I would have been perfectly right but I made a mistake while measuring.
To improve my results, I would use a wider range of concentration and different acid solutions. This would help me to find a pattern and come to a firm conclusion.

Overall I think that this experiment was a success as I have proved that concentration does affect rate, and I have also found that when the concentration is doubled the rate of reaction is halved. To draw a firm conclusion I would need to get more results, less inaccuracies and better measuring methods.