Methyl Orange Lab

The procedures for experiment A, B, and C all start the same. The first step is to put on goggles and get the data collection device set properly. The labquest needs to be plugged into the colorimeter accurately so that a click is heard when putting it in. The labquest needs to be reading digitally and the colorimeter needs to be set to 635 nm. Then shake the chloroplast solution and take a clean cuvette and fill it with 3 mL of distilled water, 3 drops of the chloroplast solution, and cap it. This is used as a blank to calibrate your labquest. Double check that the labquest is reading absorbance, this assures that the colorimeter is plugged into the labquest accurately. Insert the blank into the colorimeter and hit the calibration button. Take out the blank and empty it. The labquest is now set to experiment with. Make sure that the heat bank is set in front of the lamp and that the lamp is on. The cuvette must be placed on the opposite side of the heat bank in the path of light in the box so that no other light can interfere with the experiment.

The solutions are mixed in small amounts in cuvettes and inserted into the colorimeter, which reads the percentage transmittance during the time period. The colorimeter has an enclosed space for the cuvette to be inserted making sure light from other sources does not interfere with the reaction, hence providing accurate results. The rate of the reaction is determined by using the equation: Rate= k [CV+] [OH-], where k is the rate constant for the reaction.

When making the absorption graphs for the yellow 5 and yellow 6, the lines of best fit were giving numbers that were extremely small. After help from the TA, it was found that our concentrations used where twice as small of a concentration compared to what was actually used for Full Throttle. To correct this the molarity’s were multiplied by ½. For example when finding the x value in our equation y=2.044x+0.2067 the answer is x = 7.28-5 moles. To correct this, that number is multiplied by 0.5 to get the correct value of 3.64*10^-5. This new number is what was used in the equation c1v1=c2v2. After the solution was made to mimic Full Throttle it was discovered that the beverage only had one food dye. The experiment was intended to have a beverage with two food dyes present. To make up for this, orange PowerAde was used and the experiment was repeated for orange PowerAde. The solution was made for the orange PowerAde and its absorption graph was compared to that of the diluted orange PowerAde solution. Comparing the two graphs, have the same peaks although these peaks are at different absorption levels. Since the two graphs have the same peaks it is safe to assume that the same food dyes are present in both solutions. It is important to note that there are two peaks in each graph despite only seeing one peak. This is because both peaks are located so close to each other that they merge as one overall peak. When comparing the two

In this experiment 10 cuvettes were filled with the appropriate dilution, an additional cuvette should be filled with distilled water which should be used to calibrate the colorimeter. Record the absorbance and transmittance for each dilution generated from the Webquest. Additionally, two samples of Gatorade contains Blue Dye #1 (Low Calorie and Glacial Frost) were tested and found that the Low Calorie Gatorade had an absorbance of .135 and the absorbance of the Glacial Frost Gatorade was .153. Using linear regression the concentration of the two samples can be found if the value of transmittance is substituted for the Y value. The concentration of sample 1 is 62.8 µM and the concentration of sample 2 is 69.68 µM respectively reporting in four significant

This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment’s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students’ writing of lab

Results: There were different food dyes, solutions, beakers, chromatography strips, Erlenmeyer flasks, tooth picks, and watch glasses on the lab tables. There was also a ruler and a pencil. The first thing I did was prepare two strips of chromatography paper as instructed in the procedures. Next I used a toothpick

Parafilm was used to avoid spillage of the solutions in the test tubes. Test tubes were gently inverted every two minutes to create a well-mixed solution because the chelating agents eventually settled. xi. After 10 minutes the catechol was added to test tubes 1-4 and the blank tube was used to calibrate the spectrophotometer. Test tubes were read one after the other after the blank tube, and the transmittance of light was measured and recorded in a

In the second table below we have the graphs that show the trends of absorbance vs. concentration of the individual dyes that had a similar wavelength and absorbance to the given solution.

After it reached 1 minute, the tube was removed, and the absorbance was collected using the spectrophotometer. The experiment was repeated until we have 5 readings. For tube #2, 0.5 ml of DCIP and 2.5 ml of CMS was added, and it was shaken up until it was well mixed. After that, test tube was put into the light box using a white light for 1 minute. After that, the absorbance was taken until we have 5 readings.

In this third experiment, I used different colors of filters within the laboratory and see how the wavelengths of light

The materials needed for this lab were a lead pencil, quarter, eleven centimeter filter paper, a wick that is made out of filter paper, metric ruler, and a stopwatch. The lab also needed a petri dish, paper towel, a solvent that has ninety one percent of isopropyl alcohol, six different inks, and a pipet.

However, because the solutions were not mixed long and thoroughly enough, this made further deviations from what the data should have looked like. These errors made the absorbance values measured by the SpectroVis off from what it should have been. The next step, which was to calibrate the SpectroVis with a Blank, was crucial. For this specific lab, a Blank was a plastic cuvette filled 3/4th with distilled water.

Logger Pro was used to create graphical analyses in which Beer’s law calibration curve produced a linear regression equation of A = 4.744x104 (M) + 0.006302— resulting in a R2 value of 0.9998. This yielded a graph of absorbance vs. concentration. During the lab, two 50 ml beakers were obtained and used for dilution; the first one was filled with 10.00 ml of H2O and 10.00 ml of CV; and the second beaker was filled with 10.00 ml of the first beaker and 10.00 ml of NaOH. After the reaction mixture was obtained, it was then placed in the colorimeter at a wavelength of 565 nm. Logger Pro collected absorbencies at given times until the reaction mixture reached an absorbance around 0.20— resulting in an absorbance vs. time graph.

Then these were placed inside the spectrophotometer in order to gather the value for absorbance. A

They fall along the best fit-line, producing an R2 value of 0.99726. The equation that represents the relationship between absorbance and concentration is y= 0.017x + 0.1733. Next part of the experiment was to determine the absorbance of 2 unknowns at both high (100μl) and low (10μl) concentrations. The result is shown in table 2