How Does the Number of Pieces of Potatoes Affect the Rate of Reaction

Overview

Catalase is an enzyme (a biological catalyst) that speeds up the rate of breakdown of (H202). Hydrogen peroxide is toxic to cells so it must be broken down to water and oxygen very quickly. All cells catalase.

Hypothesis

I feel that exposing more surface area of the potato, will increase the chemical reaction, and the enzyme will break down quicker, causing more foam to be produced. Hydrogen peroxide will breakdown to oxygen and water in the presence of Catalase. The reaction will increase with more surface area to cover. However, when there is less potato pieces, meaning less surface area the increase in rate of reaction is limited and will have little effect..

Experiment

I cut 5 cylinders of potato , that were similar in size, I then cut each separate cylinder of potato in to different pieces, the groups were 5, 10 . 20, 30 and 50 pieces.

I then placed the pieces in to separate 50cm3 measuring tubes. The next stage was to add 15cm3 of hydrogen peroxide. I then started the stop clock and timed the experiment for exactly 3 minutes. The data obtained from this investigation has been recorded in a table showing the time, and the amount of pieces of potato. This means that the results of the experiment are presented in a clear and orderly fashion that allows patterns in the results to become more obvious.

Results Table

Number of pieces of potato Volume of foam produced in 3 minutes Mean average of volume of foam /cm3

5 3, 4.5, 5, 6.5, 7, 8, 13 6

10 5, 6, 9, 10, 11, 11, 11.5 9.1

20 7, 8, 10, 11, 11.5, 13, 25 12.21

30 8.5, 11, 12, 12, 17, 17, 14.25

50 15, 26 20

Conclusion

My hypothesis was correct, as you can see from the above results table, the more pieces of potato the more foam was produced, this is due to the fact there was more surface area for the chemical reaction to work on.

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