User:Alicia Rasines Mazo/Notebook/CHEM-581 Experimental Chemistry I/2014/10/08

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Tasks for October 8

  • To perform diffusion
  • To continue film synthesis from Oct. 3

Diffusion

Procedure followed as described by Dr. Hartings on Oct. 1

  1. Use sample of PVA/clay film
  2. Set the film between the two chambers
  3. Add liquid to each chamber
    1. One chamber gets water
    2. The other chamber gets 20ppm Malachite green
  4. Withdraw 200uL from each chamber at the 5 minute mark and place in their own eppy tube
    1. NOTE: I want the groups to coordinate so that their 5 minutes don't overlap with one another.
    2. NOTE: You'll want to use a small volume cuvette
    3. NOTE: You'll also want a 0minute measurement for each.
    4. NOTE: You'll likely have to dilute the sample from your chamber with the 20ppm. So, when you return the sample, only return the non-diluted sample.
  5. Measure the UV-Vis spectrum for both samples. Return each to the chamber it originally came from
  6. Take measurements at the following times
    1. 15 minutes
    2. 30 minutes
    3. 1 hour
    4. 2 hours
    5. right before you leave lab
    6. It would be great if someone could stop by on Thursday to take a measurement then.
    7. You'll be taking measurements on Friday too.
  7. During each of this, it would be best to start working up the data right away.

Preparation of 20 ppm MG green

Starting from a 195 ppm MG stock solution, 1.026 mL were added to a 10 mL volumetric flask and made up to the mark with distilled water.

    • 195v1=20(10mL); v1=1.0256mL

UV-Vis absorbance was used to determine the concentration of the dilution made. Because of detection limits, the '20 ppm' MG solution was diluted by a factor of 10.

    • 20v1=2(10mL)

Using absorbance values at 615 nm and calibration curve for MG obtained on Sept. 5, the actual concentration was found to be 20.34ppm and the stock solution from which the dilution was made: 198.39ppm.

Completion of film synthesis

Placed film in sodium sulfate, 1% HCl and sodium bicarbonate.