Honors Chemistry – Yellow
Blue Beaker Experiment Lab Report
8/20/15
Blue Bottle Experiment
Problem:
The purpose of this lab was to determine the oxidation rate of the Methylene blue solution when tested with varying amounts of solution.
Background:
The Blue Bottle Experiment is a classic demonstration of a Reversible oxidation-reduction reaction with an alkaline solution of glucose that acts as a reducing agent. It is known that, “Methylene blue speeds up the reaction, acting as an oxygen transfer agent.” (http://www1.chem.leeds.ac.uk/delights/texts/expt_1.html) When the solution is shaken it oxidizes and returns to its dark blue form, then once all the oxygen is reduced it returns to its clear state.
http://www.nuffieldfoundation.org/practical-chemistry/blue-bottle-experiment …show more content…
In separate jars, 10mL, 20mL, 30 mL, and 40mL, was added after being measured in a beaker. The dependent variable was the time it took for the solution to return to a clear color, after being shaken for 15 seconds to turn it into a dark blue. After being shaken, the time it took to return to clear was taken on a stopwatch and recorded. For each trial sever factors were kept constant: the type of solution, beaker, type of jars, duration of shaking, and the person timing. The control from the experiment was the average from all 12 trials.
Hypothesis:
If 10mL, 20mL, 30 mL, and 40mL of solution are added to four separate beakers, then the beaker containing 10mL will take the longest amount of time to return from blue, back to clear after being shaken for 15 seconds. …show more content…
The collected data supports the hypothesis that stated: “If 10mL, 20mL, 30 mL, and 40mL of solution are added to four separate beakers, then the beaker containing 10mL will take the longest amount of time to return from blue, back to clear after being shaken for 15 seconds.” The hypothesis is supported by the data’s demonstration of the 10mL jar taking the longest to return to a clear color, at an average of an average of 59.5 seconds. Possible sources of error could include: changing the person shaking for trial 3, inaccurate timing, and inaccurate measuring of volume. These sources of error could be eliminated by: using the same person to shake for all trials, more precise timing, and measuring. By preforming this experiment the observation of how glucose reduces the methylene blue to a clear state when oxidized, is observed. Therefore demonstrating, how concentration levels of oxygen effect methylene blue, when in the presence of glucose. Also, it was learned how different volumes of the solution effect the reaction rate. Based on this experiment, other variable such as shaking duration and lid presence could be further investigated. Also, another questions that that be explored could be “If the jar was completely filled, would shaking still produce the blue