Chemistry Experiment

Chemistry Experiment

An investigation to find out how the rate of the reaction of

hydrochloric acid and sodium thiosulphate solution is affected by the

concentration of the sodium thiosulphate.

I am going to investigate the effect of varying the concentration of

sodium thiosulphate solution in a reaction with hydrochloric acid. The

theory behind this experiment is that 'increasing the concentration

can increase the rate of the reaction by increasing the rate of

molecular collisions.'

[IMAGE]Sodium Thiosulphate + hydrogen acid sodium chloride + sulphur

+sulphur dioxide + water

Or

[IMAGE]Na SO (aq) +2HCL (aq) 2NaCL (aq) + SO (I) + SO (g)

Plan

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Prediction

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I predict that the greater the concentration of sodium thiosulphate

solution the faster the chemical reaction will take place. Therefore,

the cross will disappear more quickly due to the cloudiness of the

solution. I think that the concentration of a solution effects the

rate of reaction because 'the rate of reaction depends on how frequent

the particles of the reacting substances collide. A more concentration

substance has more particles for a given volume than a more dilute

substance, because there are more particles about, the frequency of

successful collisions is greater and the reaction will happen faster.

So if I double the concentration I will double the rate of reaction.

Equipment

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* Burette

* Conical flask

* Beaker

* Stopwatch

* Paper with cross marked on it

* Sodium thiosulpate solution

* Hydrochloric acid

* Water

Safety

To conduct my experiment safely I will follow normal laboratory rules,

which include:

* The wearing of safety goggles to protect my eyes from chemical

splashes.

* Standing up to conduct the experiment, therefore reducing the risk

of tripping and spilling chemicals.