# How the temperature would affect the rate of reaction between Sodium Thiosulphate and Hydrochloric Acid.

Aim: How the temperature would affect the rate of reaction between Sodium Thiosulphate and Hydrochloric Acid.

Sodium      +   Hydrochloric                  Sodium + Sulphur +     Sulphur + Water

Thiosulphate           Acid                           Chloride     Dioxide      (Precipitate)

Na2SO2O3(aq) + 2HCL(aq)          2NaCL(aq)+ SO2(g) + S(s) + H2O(l)

I will use how quickly it takes for me not to see a cross under the conical flask of this reaction.

Prediction: I predict that as the temperature is increased the rate of reaction will increase. This means if I plot a graph of time against temperature my graph will have a negative correlation and will be curved as the increase in rate of reaction will not be exactly the same as the temperature is increased. This can be justified by relating to the collision theory. When the temperature is increased the particles will have more energy and will move faster. Therefore they will collide more often and with more energy. For a reaction to occur, particles have to collide with each other. Only a small percent result in a reaction. This is due to the energy barrier to overcome. Only small particles with enough energy to overcome the barrier will react after colliding. The minimum energy that a particle must have to overcome the barrier is called the activation energy.

The size of this activation energy is different for different reaction. Particles with more energy are more likely to overcome the activation energy barrier to reaction and will react successfully. If the frequency of collision is increased the rate of reaction will increase. However, the percentage of successful collisions can be achieved by increasing concentration, pressure, surface area or adding a catalyst. However the rate of reaction would decrease if all or any of the above factors are decreased or if a catalyst is removed from a reaction mixture.

Concentration – If you increase the concentration of a reaction solution you will increase the number of reacting particles in a given volume. Doing this will increase the chances of a successful collision.

Pressure – If the pressure is increased the particles in the gas are pushed closer. This increases the concentration and will increase the rate of reaction.

Surface Area – If you increase the surface area of a reacting solid you will make available more reacting solid particles therefore increase the chances of a successful collision. To increase the surface area of a reacting solid you powder it.

Catalyst – The ...