In this investigation I am going to examine if the concentration of hydrogen peroxide affects the rate at which it is broken down by enzymes in the liver known as catylase.

To keep this investigation fair the experiment will need to carried out  more than once (in this case 3 times) to gain better average results.    The liver will need to be kept at the same temperature, as this could affect the rate at which the catalysts inside it work.  

The amount of hydrogen peroxide and water will need to be measured very carefully.

The stopwatch will need to be started when the water and hydrogen peroxide are poured over the liver and stopped after exactly a minute.

To keep this investigation safe plastic gloves will need to be worn to prevent hygrogen peroxide making contact with the skin and to stop any germs on the liver spreading.  Safety glasses will also need to be worn to prevent hydrogen peroxide splashing into the eyes.  After the experiment your hands will need to be washed incase any hydrogen peroxide did make contact with your skin.

Here are the tables of the results from my three experiments:

      %        Amount of                Amount        Total Amount        Volume of

Solution        Hydrogen                of Water        of Solution        Oxygen Produce

                Peroxide (ml)        (ml)                (ml)                        in 1 Minute (ml)

10                5                        45                50                        10

20                10                        40                50                        60

30                15                        35                50                        120

40                20                        30                50                        170

50                25                        25                50                        320

60                30                        20                50                        330

70                35                        15                50                        380

80                40                        10                50                        400

90                45                        5                50                        420

100                50                        0                50                        440

      %        Amount of                Amount        Total Amount        Volume of

Solution        Hydrogen                of Water        of Solution        Oxygen Produce

                Peroxide (ml)        (ml)                (ml)                        in 1 Minute (ml)

10                5                        45                50                        5

20                10                        40                50                        40

30                15                        35                50                        110

40                20                        30                50                        140

50                25                        25                50                        180

60                30                        20                50                        210

70                35                        15                50                        250

80                40                        10                50                        310

90                45                        5                50                        350

100                50                        0                50                        380

      %        Amount of                Amount        Total Amount        Volume of

Solution        Hydrogen                of Water        of Solution        Oxygen Produce

                Peroxide (ml)        (ml)                (ml)                        in 1 Minute (ml)

10                5                        45                50                        10

20                10                        40                50                        30

30                15                        35                50                        90

40                20                        30                50                        130

50                25                        25                50                        170

60                30                        20                50                        220

70                35                        15                50                        230

80                40                        10                50                        280

90                45                        5                50                        320

100                50                        0                50                        350

I then produced a results table to show my average results :

      %        Amount of                Amount        Total Amount        Volume of

Solution        Hydrogen                of Water        of Solution        Oxygen Produce

                Peroxide (ml)        (ml)                (ml)                        in 1 Minute (ml)

10                5                        45                50                        8.33

20                10                        40                50                        43.33

30                15                        35                50                        106.66

40                20                        30                50                        146.66

50                25                        25                50                        223.33

60                30                        20                50                        253.33

70                35                        15                50                        286.66

80                40                        10                50                        330

90                45                        5                50                        363.33

100                50                        0                50                        390        

My results show that my prediction was right.  The higher the concentration of hydrogen peroxide the more oxygen was produced.  The reason why this happened was because enzymes in the liver known as catylase reacted with the hydrogen peroxide and broke it down into oxygen and water.  The reason why as the concentration of hydrogen peroxide was increased the more oxygen was produced was because for the hydrogen peroxide particles to react with the liver they had to collide with it.  Increasing the amount of hydrogen peroxide meant there would be more hydrogen particles in the same volume of solution.  This would increase the chances of the particles colliding with the liver and reacting with it.            

A 10% Solution Of                                         A 20% Solution Of

Hydrogen Peroxide                                        Hydrogen Peroxide

When the solution is doubled there is twice as much chance of the hydrogen peroxide particles colliding with the liver.

I did have 2 anomolous results.  These could be wrong for number of reasons :

There could have been a change in room temperature, causing enzymes in the liver to work at a different rate.

Too much or not enough hydrogen peroxide or water could have been added.

The stop-watch could have been started to early or to late, or could have been faulty.

I could make my investigation better by :

Doing my experiment more times to obtain better average results.

Keeping the liver at the same temperature throughout the experiment.

To investigate further I could :

Investigate how temperature affects the way enzymes in the liver work.

Investigate how much hydrogen peroxide would be needed to produce a certain amount of oxygen.

Investigate how long it would take for hydrogen peroxide to produce a certain amount of oxygen.

Investigate how the size or surface area of the liver would affect the amount of oxygen produced.