The higher the temperature of the solution, the higher the rate of reaction.
By measuring the time taken for the formation of sulphur precipitate (yellow solid) when sulphuric acid, H2SO4 reacts with sodium thiosulphate(VI), Na2S2O3 of different temperature, we can investigate the effect of temperature of the reactant on the rate of reaction.
- 50 cm3 of 0.2 mol dm-3 sodium thiosulphate solution at 30ºC + 10 cm3 of 0.5 mol dm-3 sulphuric acid.
- Time taken for the ̔X’ sign placed under the conical flask to disappear from view is recorded.
- The experiment is repeated by using sodium thiosulphate solution with temperature 35ºC, 40ºC, 45ºC and 50ºC.
- The graph for temperature of sodium thiosulphate (VI), Na2S2O3 against time taken for the sulphur precipitate to formed is plotted.
- As the temperature of sodium thiosulphate solution decreases, the longer the time is needed for the marked ̔X’ to disappear.
- The graph for temperature of sodium thiosulphate (VI), Na2S203 against 1/time taken is plotted.
- As the temperature of sodium thiosulphate increases, the value of 1/time increases. We should note that 1/time = rate of reaction.
- The higher the temperature of sodium thiosulphate solution, the higher the rate of reaction .