How Does The Concentration Of Distilled Water Affect The Rate Of Photosynthesis Lab

Abstract: Photosynthesis is a metabolic process common to plants. The process utilizes inorganic CO2 to produce sugars. The waste product of this metabolic reaction is oxygen. There are several factors which can influence O2 production of photosynthesis such as increase in temperature, increase in light intensity, etc. In this experiment, the effect of varying CO2 concentrations on an aquatic plant species is examined. It is hypothesized that different concentrations of CO2 ¬will yield different amounts of O2 production. This is tested by submerging the aquatic plant, Elodea densa, into solutions of different CO2 concentrations. The control trial is run with the plant submerged in distilled water. In order to minimize other potential factors,

The results of each statistical calculation (sample size, mean, calculated t-values, degrees of freedom and p-values) are displayed in Table 1. Mean is calculated by the summation of a data set followed by division by the sample size. This is repeated for each set of treatment data as well as the control (dH2O). The calculated t-values are derived from the absolute value of the difference between the mean of distilled water and the treatment, divided by the square root of the summation of both squared SEM values. The values used for distilled water remain the same throughout the data. Calculated t-values, p-values and means are the only values which vary between comparisons. However, all p-values are found to be smaller than 0.05. The treatment with the greatest mean Oxygen production comes from the more highly concentrated Sodium Bicarbonate solutions (such as the 1.0% NaHCO3 solution). Whereas the lower values of mean Oxygen production are found in the lower concentrations of Sodium Bicarbonate solution, as shown in Figure 1.
Table 1: Statistical calculations using a sample of laboratory data supplied by Kewei Xu. Sample size, mean O2¬, calculated t-value, degrees of freedom and P-value were determined for each comparison between distilled water and various concentrations of Sodium Bicarbonate.Figure 1: Displays the average amount

It is said that more than 90% of all studies prove elevated CO2 has positive effects on plant growth, O2 yield and photosynthesis (Dubey et al. 2015). For example, a study completed on Sedum alfredii, an herb common to Asian countries, was found to produce higher photosynthetic rates and greater O2 production while exposed to levels of CO2 that are greater than ambient atmospheric amounts (Li et al. 2015). However, there is an ambiguity in the data. The mean O2 production for the 0.4% NaHCO3 solution is greater than that of the 0.6% solution although it was predicted that O2 production would increase with concentration. This ambiguity could be attributed to an error in the method. Perhaps the rubber stopper was placed incorrectly leaving air bubbles inside the tube. There could have also been a contamination error in the 0.4% solution which resulted in a higher concentration, and thus, higher O2