Sodium Thiosulphate Rates of Reaction

Sodium Thiosulphate Rates of Reaction

During this investigation I am going to investigate the rates of

reactions and which changes will affect this rate. A rate of reaction

is when a reactant is lost or a new product is formed during a

chemical reaction. I am going to investigate the effect of

concentration by mixing Sodium Thiosulphate, Hydrochloric Acid and H2O

(water) until the reaction takes place and the mixture goes cloudy and

the newspaper beneath the flask can no longer be read. Both the Sodium

Thiosulphate and the Hydrochloric acid are soluble in water, so the

concentration of either can be changed. However I am going to use

varying amounts of Sodium Thiosulphate acid and H2O but I will keep

the amount of Hydrochloric Acid constant. This is difficult factor to

investigate as the readings are recorded by human reactions, which

could differ due to the inevitabilities of a human error.

According to the collision theory of reacting particles there are five

different factors, which could affect this rate of reaction, these

are:

* Temperature

* The concentration of the solution

* The pressures of the gases

* The surface area if using solid reactants

* Catalysts

I predict that when I use the highest concentration of Sodium

Thiosulphate the reaction will occur much faster then when I use a

lower concentration. I predict that there may be a pattern to the

results because the concentration is decreasing in equal amounts and

therefore the rate of reaction may do too. This is because for a

reaction to take place particles have to "collide" with another but

only a small percentage of these "collisions" result in a reaction. If

I increase the amount of particles then they are also more likely to

collide with each other and therefore the reaction should also occur

much faster, even though the amount of successful collisions remain

the same.

To complete this investigation I think I am going to need to use the