Investigate how the surface area affects the rate of reaction between catalase from a potato and hydrogen peroxide.

Number of readings

I will be repeating this experiment twice or maybe three times on anonymous results to make sure I am getting the most accurate result I can.

Range

The range of potato will be form a whole (3cm chip) to slices of a sixth of a 3cm chip. This will be done by measuring the chip with a ruler and cutting it into equal parts.

Method

First my partner and me got out apparatus and set it up as shown below. We then put safety goggles on to protect our eyes and filled up the syringe with 20ml of hydrogen peroxide. Then we put a 3cm chip of potato in a beaker and blocked the top off with a cork. We then put a measuring cylinder into the water and made sure it didn’t have any air bubbles in it, we stood it up slanted in the water so there was a gap to fit the rubber tube. Then we fixed the syringe to the tube of the beaker and squirted in the hydrogen peroxide, we waited a few seconds for the air to come out of the tube and then we put it into the measuring cylinder.
       Gas was coming out of the beaker from the reaction with the potato and going through a tube into the measuring cylinder. After all the air was out we started the stopwatch, and waited to see how long it would take to fill 10 cubic cm of the cylinder. We then repeated the same experiment but made the surface area of the potato bigger.





















Results 

Analysis
Conclusion

I have come to the conclusion that as the surface area of the potato gets bigger the rate of reactions gets faster (the quicker 10 cubic cm or gas is produced). This happens because as the surface area increases, the speed of the reaction will increase therefore the gas will be produced faster. I believe this because most chemical reactions happen faster when there is more of the reactant to react with. When there is a larger surface area, there is more of the reactant available, which makes it easier for them to react together. Usually, when the surface area is doubled it will double the rate of reaction.
Chemical reactions take place by chance. Particles need to collide with enough velocity so that they react. As the surface area is increased the particles have a bigger surface to react with so more molecules can react at a time. This means that they are colliding more often and there is a bigger chance that the collisions have enough velocity to cause a reaction. Since there are more collisions the chemical reaction takes place faster.

Evaluation

My results are quite accurate but I did get one anomalous result, this was probably because on the previous experiment I didn’t wash out the beaker properly, a human error. One thing I saw which could be improved is that I had to keep the hydrogen peroxide moving over the potato so that all the potato go a fare share of the hydrogen peroxide. This could perhaps be improved by putting more than 20ml in so the whole potato is covered or by using smaller equipment. Another thing is that the room temperature varied, in that as more people came in the room the temperature rose, so this could make the experiment go faster. I could also make improvements by comparing my results to others in the class and seeing what they got.