Camille CheungWe soaked 250 beans in 500mL of each nitric acid solution, and left them overnight. On the day of the experiment, we set up our materials (which included a carbon dioxide gas pressure probe, spoons, vernier lab pro software, and the beans). We started with a pH of 7 and went down to 3. There were 30 trials in total, with 5 for each pH. Using the spoon we counted 50 beans and placed them into the carbon dioxide gas pressure container. After that we used the computer to measure how much carbon dioxide was produced.
This is a table of the data collected. It shows the rates of carbon dioxide produced. This graph is an example of one trial. We measured the rate at which carbon dioxide was produced.
Nadine SteinerIn this table we found the average of each pH. We then took out the outliers and found that the averages were consistent and increasing at a linear rate. So then in this graph it shows that the lower the pH level, the lower the amount of carbon dioxide produced. Although it is not shown on the slide, we did a control run with no beans in the container of the carbon dioxide gas pressure probe. The amount measured was 850ppm. This value represents how carbon dioxide is already present in the bottle, which may have had an affect on the data. However we just assumed that this value remained constant throughout the experiment.
Judy JoWeaknesses:Closed system leakage of carbon dioxideSome beans were soaked for a longer timepH of nitric acid was not fully accurate; there were problems with the pH meterSystematic errors with the carbon dioxide gas pressure probeSome beans did not germinate because they were inactiveSome carbon dioxide was in the system from the atmosphere, thus giving a higher value of ppmOverall, our experiment concludes that the higher the pH of nitric acid, the lower the cellular respiration rate of soybeans. This can be applied to any other acid with various other beans (but to different extents), depending on the type of bean. This correlates to how acid rain in our environment decreases the rate of cellular respiration in plants and beans, which ultimately --------------------------------------.Improvements Having the same type of probeMore accurate timepH – more accurate meter (different one or one that has already been calibrated)Organic soybeans? – same beans from one population