Hydrogen Peroxide Lab Report

Introduction:
In liver cells, hydrogen peroxide is produced as a bi-product of some metabolic reactions. Hydrogen peroxide is a highly active chemical used in household products for bleaches and cleansing wounds. In a cell its build up would be highly toxic. However, liver cells contain an enzyme, catalase, which immediately breaks down hydrogen peroxide. It is a peroxidase and breaks up the toxic hydrogen peroxide to water and oxygen which are both nontoxic. The reaction is exothermic, meaning that energy is released in the form of heat. It is the fastest known enzyme.
Hydrogen peroxide  Water + Oxygen
2H2O2 2H2O O2

List of materials:
Safety glasses Iron powder in a watch glass 5cm3 liver extract in a small beaker
4 large test tubes in
Wash off any spills with plenty of water.
Carry out the following experiments as shown below:
Experiment Materials
1 Add 1 small spatula of iron powder to 1cm3 distilled water followed by 4cm3 H2O2
2 Add 1 small spatula of iron filings to 1cm3 distilled water followed by 4cm3 H2O2
3 Add 4 iron nails to 1cm3 distilled water followed by 4cm3 H2O2
4 Add 1cm3 of liver tissue extract, 1cm3 distilled water followed by 4cm3 H2O2
5 Add 4cm3 H2O2 to 1cm3 distilled water followed by 1cm3 of liver tissue extract

Results and observations:
Experiment Observations
1 The iron powder started to bubble after a short delay when the hydrogen peroxide was added in the test tube. The grains of the iron powder sank to the bottom and very small bubbles were released. When compared to experiment 2, the sizes of the bubbles were smaller but there were more bubbles.
2 The iron filing started to bubble after a short delay (slightly longer than the delay in experiment 1). When the oxygen bubbles were getting released, they picked up iron filings and rose to the surface with the flakes. After about 15 minutes, they formed a layer above the surface and we could observe a layer of gas (O¬¬2) trapped in between the layer of iron filing and the surface of the
No bubbles were released.
4 When the hydrogen peroxide was added to the water and liver that was in the test tube, there was a very rapid and instantaneous reaction. As soon as the hydrogen peroxide was added, beige colored, foamy bubbles rose to the top of the beaker. After about 1 minute, the bubbles started to disappear.
5 When the liver was added to the water and hydrogen peroxide that was in the test tube, it started to react but in a less violent way compared to experiment 4. The foamy bubbles rose slowly towards the top of the test tube. Even though the reaction was slower, the total amount of bubbles produced was about the same with experiment 4.

This photo focuses on the difference between the 4th and the 5th experiment directly after the hydrogen peroxide and the liver was added to each of them. The foam filled up the entire test tube and is starting to overflow in the 2nd test tube from the right which is the 4th experiment. In contrast, there isn’t as much foam in the test tube on the far right. This can be due to the difference in time the liver gets completely soaked in hydrogen peroxide. For the 4th one, the liver is instantly soaked since hydrogen peroxide is just poured on top of it. However, in the 5th one, it takes a bit more time for the liver to completely sink