Experiment on rates of reaction.

• Put the Magnesium ribbons into two different test tubes and labeled them 1 and 2.
• Poured the 0.5 ml hydrochloric acid into No1 and the 1 ml hydrochloric acid into No2.
• Took results.

The results showed,

                        Amount Of Acid                Time

                        0.5ml Hydrochloric Acid         18 Mins (1800 Secs)

                        1 ml Hydrochloric Acid         8 Mins (800 Secs)

 

Conclusion: It seemed that the higher the concentration of acid, the quicker the reaction is going to take place.

Main Experiment:

        Aim: Our aim of this experiment was to investigate the effect of concentration on rates of reaction using different concentrations of sodium thiosulphate and hydrochloric acids.

        Prediction: I thought that the higher the concentration that we used, the test was going to be a lot quicker but the lower the concentration, the test was going to be much slower.

        Safety: We had to take safety precautions in case something went wrong. We needed water taps near by in case some one got acid in their eyes and we also needed goggles, gloves and a cloth.

        

Fair test:  

                Keep the same               Change               Measure

                

                Amount of acid                                         Amount of acid

                        Size of ribbon

                        Size of test tube

Method: 

• The method we used for this experiment was simple. First we marked a piece of plain paper with a large ‘X’.

• We then place o beaker in the centre of the ‘X’.
• We then had to pour 10g/h of Sodium Thiosulphate and 10g/h of Hydrochloric Acid into the beaker and start the clock.
• When the mark on the paper started to fade, we had to stop the clock and record the time we received.
• We had to repeat this method for each concentration of Sodium Thiosulphate.

        Results:  We had to record our results in a table as shown;

        Concentration of Sodium Thiosulphate (g/h)                Time (Secs)

                                                                1st                2nd

                        10 g/h                                        98.02                97.06

                        20 g/h                                        65.22                63.16

                        30 g/h                                        45.56                44.62

                        40 g/h                                        34.43                32.39

        Conclusion: From my prediction, when you increase the concentration of an acid, the rate of the reaction will increase. A reason for this is that the chemicals in the concentration make the rate of the reaction faster or slower.

     My table of results support this because when the concentration of Sodium Thiosulphate was 10 g/h, the time it took to react was 98.02 seconds but when the concentration was 20 g/h, the reaction took 65.22 seconds on continued to get quicker each time I raised the concentration.

        Evaluation:  My experiment went O.K because it was a fair test and I used everything correctly. I think the method I used was also good because I was able to carry out the whole experiment perfectly with good results.

     I think there was some room for improvement because if the room temperature was kept the same, the results would have been more accurate. I could have used a Burette to make sure my measurements were exact. I could have used a Light Sensor to improve the timing, it tells you when the reaction has taken place. I could have also used Data Log Equipment on the computer, which would give me the exact result tables and graphs.

     I would repeat this experiment several times to make sure I collected all the right results.