The Data

Raw Data:

Figure 1
The concentration of dissolved oxygen in 100mL of water after 2 minutes of shaking at various temperatures. (In mg/L) +/-.1mg/L

Temperature Range (°C) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 0-7 | 4.8 | 6 | 9.9 | 4.1 | 4.8 | 6.3 | 7.5 | 4.8 | 12-17 | 7.0 | 6.8 | 7.8 | 4.6 | 5.7 | 6.8 | 7.3 | 5.5 | 22-27 | 7.2 | 7.2 | 7.4 | 5.3 | 7.1 | 7.8 | 6.8 | 7.5 | 32-37 | 6.4 | 6.2 | 6.3 | 5.4 | 8.6 | 6.8 | 6.2 | 8.5 | 42-47 | 5.6 | 6.2 | 7.4 | 5.6 | 7.8 | 7.9 | 4.9 | 7.4 | Instrument Precision: +/- .1mg/L Estimated Uncertainty: +/- 1mg/L This is due to the instrument precision limitations along with the various errors in the calibration of the LabQuest which lead to differences for each temperature value. Also inconsistencies inside of the temperature ranges between samples will cause different values. Processed Data: Figure 2
The concentration of dissolved oxygen in 100mL of water after 2 minutes of shaking at various temperatures. (In mg/L) +/-.1mg/L Temperature Range (°C) | Dissolved Oxygen (mg/L) | Standard Deviation | 0-7 | 6.03 | 1.91 | 12-17 | 6.44 | 1.07 | 22-27 | 7.04 | 0.761 | 32-37 | 6.80 | 1.15 | 42-47 | 6.60 | 1.16 | (4.8+6.0+9.9+4.1+4.8+6.3+7.5+4.8/8)=6.03mg/L Standard Deviation in Calculator

Data Presentation:

Conclusion and Evaluation: Conclusion: The data shows an increasing concentration of dissolved oxygen up until a peak at 22-27 degrees Celsius and it declines for the next two temperature ranges. This data shows no trend and there is no proportional change between any of the values, which would suggest any useful findings. Due to these irregularities in the data, it can be inferred that the lab was a failure in attempting to identify the trend between the temperature of water and the concentration of the dissolved oxygen at each temperature. The trend of the concentration of the dissolved oxygen should have shown an inverse relationship to the change in temperature. The higher the temperature of the water, the less soluble the water is for the solute of oxygen. The change in temperature will change the amount of dissolved oxygen in the water to create a dynamic equilibrium for each new temperature. At colder temperatures the oxygen is more soluble in the water and therefore the concentration of dissolved oxygen in water in inversely proportional to the temperature of the water. The colder the temperature, the higher the concentration of dissolved oxygen and the hotter the temperature allows less dissolved oxygen (Olson). Evaluation: The design of the experiment was not so flawed as was the method of the experiment. Every lab group in the class was using a different Dissolved Oxygen Probe, which had been calibrated by a different person and each was calibrated to a different solution. This led to very different calibrations for each group’s Dissolved Oxygen probe and led to very different readings for each variable being tested. Also on the second day of the lab, some groups used a different probe than they did the day before which led to different readings off of a different calibration which threw off any chance of attaining proportional data or data with a trend. Also the shaking containers threw off the data as they were sometimes broken and they leaked water and some allowed more oxygen to move into and out of the container through these holes. This would skew the data by altering the amount of oxygen that is available to dissolve into the water. Also this made water leak which made the amount of water sometimes drop from 100mL to less which will cause different amounts of oxygen to dissolve and throw off the reading. The temperatures inside of each of the temperature ranges were not always proportionally different from the ones used in the previous treatment group. This would lead to different temperatures being used by each group and would result in different oxygen