# To investigate the effect of temperature on the rate of reaction

Title: To investigate the effect of temperature on the rate of reaction.

Objective: To study on how temperature relates to the rate of reaction.

Procedures:

1. 5cm3 of the hydrochloric acid is added to a boiling tube.

2. 20cm3 of the sodium thiosulphate solution is added to another boiling tube.

3. Draw a large cross on a piece of paper* and a beaker is placed over it. A heat-resistant mat is put under the paper.  (*In the experiment, the heat-resistant mat is directly drawn with a cross, so that we did not need to draw it on a sheet of paper.)

4. Another beaker which contains water is prepared.

5. The two boiling tubes are put inside the beaker for a hot water bath, both with a thermometer*. In the first time of the experiment, this step is skipped because the experiment is done in room temperature, but a thermometer is still put into a boiling tube to measure the temperature.  (*In the experiment, we have only got one thermometer so we measured the temperature of the water bath.)

6. After both of the solutions reach the suitable temperature, they are poured into the beaker which is prepared in step 3. Start the stop watch simultaneously.

7. The solution is stirred*. A person watches the cross vertically during the reaction.  (*In the experiment, we did not stir the solution.)

8. Stop the stop-watch when the cross on the paper just ‘disappeared’.

9. Record the time in the results table.

10. Repeat step 4-9 with 2 more times*. The water in step 4 should have a temperature of 40℃ and 60℃ respectively, such that the solutions of Na2S2O3 and HCl in step 6 will have a temperature of 40℃ and 60℃ respectively before poured into the beaker. (In the experiment, we do it 4 times more for 35℃, ...