Catalase Lab Report

As it can clearly be seen in Figure 4, changes in Ph (independent variable) lead to significant changes in the mean rate of reaction (dependent variable.
It can be observed that when pH increases from 2 to 5 the mean rate of reaction (m.r.r.) increases but not to a great extend, going from 0.054%/20sec to 0.080%/20sec.
When the pH goes from 5 to 7 however we can see it going down from 0.080%/20sec to 0.070%/20sec. The most interesting change however is from pH 7 to 9 where an increase of an incredible rate can be observed. From 0.070%/20sec the rate goes up to 0.271%/20sec, reaching its maximum peak at pH 9.
After that, from pH 9 to pH 10.2 we can see that the m.r.r. drastically decreases but still remains higher than all the rest m.r.r before pH 9.
Discussion:
The results of this experiment prove my hypothesis that the pH of the catalase will alter the function of the enzyme, thus the rate of reaction will change. They also prove my other hypothesis that there is a specific pH level in which the catalase works best. However, after looking at Figure 4 we can see that that optimum pH is 9 which, as mentioned in the background knowledge section, is not what would usually be the optimum pH for catalase when conducting this experiment but would be around pH 7.
What was the cause that made the results of this

I started exploring the possibility of the existence of a chemical reaction between the N2 molecules and the molecules on the solution. In the presence of water, NaOH breaks down into Na + OH ions, which led me to consider the possibility of the Na released reacting with the N2 available, forming NaN3, decreasing the amount of N2 and making it more likely for O2 to reach higher numbers. NaN3 is a known catalase inhibitor, decreasing the activity of the enzyme, hence decreasing the amount of O2