Lab report: the effect of temperature on the rate of reaction

Dependent variable: time of the reaction

Controlled variables: the volumes of sodium thiosulphate, potassium peroxodisulphate, starch solution, potassium iodide, the mass of the beaker, the mass of the test tube

Procedure

1. Add 25cm3 of 0.2mol dm-3 of potassium iodide solution(KI), 35cm3 of 0.1mol-3 potassium peroxodisulphate(K2S2O3) solution, 20cm3 of 0.01mol-3 sodium thiosulphate (Na2S2O3)  into different burettes.
2. Add 3cm3 of 0.2mol dm-3 of potassium iodide solution(KI), 4cm3 of 0.1mol-3 potassium peroxodisulphate(K2S2O3) solution, 2cm3 of 0.01mol-3 sodium thiosulphate (Na2S2O3)  into a test tube.
3. Add 150cm3 of water into a 250cm3 beaker.
4. Heat the water until it reaches 20°C.
5. Put the test tube into the water in the beaker.
6. Start the stopwatch immediately.
7. Record the time taken for the solution in the test tube to change.
8. Repeat 1 –3 with temperatures ranging from 30 to 70°C.
9. Repeat the whole experiment again.
10. Name the first experiment, experiment 1. Name the repetition of the first experiment, experiment 2.  

Data collection

Measuring the rates of the reactions

To measure the rates of the reactions in these experiments, this equation is used:

                Rate of reaction= temperature change/ time taken

Conclusion

As the temperature increases, the rate of the change of the color of the solution increases. This shows that the rate of the reaction increases.