The Effect of Concentration on the Rate of Reaction :: GCSE Chemistry Coursework Investigation

The effect of submersion on the rate of reaction between sodium thiosulphate and dilute hydrochloric stingingThis investigation is about rates of reaction and what affects them.In this case I am going to look at hydrochloric acid and sodiumthiosulphate which is a precipitation reaction causing the solution togo cloudy. They react as in the equations to a lower placesodium thiosulphate + hydrochloric acid - sodium chloride + randomness +sulphur dioxide + waterNa2S2O3(aq) + 2HCl(aq) - 2NaCl(aq) + S(s) + SO2(g) + H2O(l)A reaction give only occur where the particles of the reactants accommodateand combine. This is called the collision theory. For a reaction tooccur particles have to collide with for each one other. Only a small percentresult in a reaction. This is due to the energy barrier to overcome.Only particles with enough energy to overcome the barrier will reactafter colliding. The minimum energy that a particle must have toovercome the barrier is called the activation ene rgy, or Ea. The sizeof this activation energy is different for different reactions. If thefrequency of collisions is increase the rate of reaction willincrease. just the percent of successful collisions stay thesame. An increase in the rate of reaction can be achieved byincreasing the frequency of collisions. Therefore to increase the rateof reaction it is demand to cause more particles to collide harderand collide more often. There argon several ways to do this and thesemake up the factors for this experiment. They are listed below alongwith predictions as to their affect on the reaction.Possible FactorsTo make legitimate I carry out a fair test I will only change theconcentration of sodium thiosulphate. I will keep the followingfactors the same.Increasing the pressure sensation. By reducing the volume in which the sameamount of particles exist the pressure is increased. Once the same go of particles are in a smaller area there is less(prenominal) space in whichto move and so the particles are more apt(predicate) to hit each other. It istherefore possible to predict that increasing the pressure will resultin an increase in the rate of reaction. I will not test this proteanbecause we dont have the facilities to test it. However pressure is acontinuous variable.Catalyst. A catalyst is a dismantle substance that speeds up areaction. After the reaction has happened it gets left behind. Thismakes this variable unsuitable for the type of experiment I am goingto do.Temperature. By giving the particles extra energy they will movefaster. This means that they process more ground and are therefore more