User:Dominique Brager/Notebook/481 Notebook/2016/09/07

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Objective

  • To prepare solutions that will be needed later for creating films and beads.
  • Prepare three PVOH films
  • Approximate the accuracy of pipettes and the purity of different kinds of water.
  • Measure how much water is really in an old sample of "anhydrous" CaCl2.

Description

  1. Took 3 different pipettes and measured accuracy by taking six measurements using water.
    • Glass vial and cap were weighed
    • p-200 pipette was set to 200µL.
    • 200µL of distilled water were pipetted and placed in vial. Vial and water was measured. This step was repeated six times for six different measurements.
    • Ahn recorded measurements for p-1000
    • Sarah recorded measurements for p-10
      • Sarah used 5 measures of p-10 each time (50µL) so as to have enough water to weigh.
  1. Measured conductivity and pH of tap, DI, HPLC and LCMS water.
    • A vial of each kind of water was filled with water and the pH and Conductivity meters were used to measure the pH and conductivity of each.
  1. Prepare several stock solutions
    • 100mL of 200ppm Malachite Green
    200ppm = 200 mg/L
    100mL*1L/1000mL*200mg/1L = 20mg
    0.02003g of Malachite Green was added to 100mL of deionized water
    • 100mL of 3%wt bentonite
    Density of water is 1g/mL
    100mL* 1g/mL = 100g
    3% of 100g is 3g
    3g bentonite added to 97mL of water
    • 100mL of 3%wt NaMT
    Same procedure used as for bentonite
    3g NaMT added to 97mL water
    • 200 mL water + 40 g Na2SO4 + 4 mL H2SO4 (conc.)
    • 250 mL 1.0 M HCl solution
    12.1 M HCl (conc.)
    M1V1=M2V2
    12.1 M HCl * V1 = 1.0 M * 250mL
    V1 = 20.8 mL
    20mL of conc HCl was added to 230 mL of deionized water
    • 250 mL 0.2 M sodium bicarbonate solution
    Molar Mass NaHCO3: 84.007 g/mol
    250mL * 1L/1000mL*0.2 mol/L= 0.05 mol NaHCO3
    0.05 NaHCO3 * 84.007 g/mol = 4.2 g NaHCO3
    4.2g NaHCO3 was added to 250mL water
  1. Prepare PVOH films
    1 g PVOH + 0.5 mL 8% glutaraldehyde in 12 mL water
    1 g PVOH + 0.1 g bentonite + 0.5 mL glutaraldehyde in 12 mL water
    1 g PVOH + variable amount of a crosslinking agent (either equivalent moles of glyoxal or a different quantity of glutaraldehyde) w/o clay
    • For each film, the contents were mixed in a small beaker and heated at 70° C until everything was dissolved
    • The solutions were then poured into small dishes and left to dry in the fume hood until next lab
    • Films were prepared by Sarah and Ahn

Data

Pipette Accuracy Data
Pipette Mass of water + Vial + Previous Water Mass (g) Mass of water (g)
p-10 (5 measures)

Mass of Vial: 14.86452g Done by Sarah

14.91830 0.05378
14.9664 0.04814
15.01317 0.04673
15.06537 0.05220
15.12257 0.05720
15.16976 0.04719
p-200

Mass of Vial: 14.98395g

15.18007 0.19612
15.38455 0.020448
15.58249 0.19794
15.78102 0.19853
15.97933 0.19831
16.16458 0.18525
p-1000

Mass of Vial: 14.88254g Done by Anh

16.01650 1.13396
16.98485 0.96835
17.95782 0.97297
18.95590 0.99808
19.94660 0.99070
20.94070 0.99410

Notes

A Karl Fischer Titration was attempted to determine the amount of water in a sample of CaCl2 that had been dried in 2014 but because of issues with the instrument no data was collected.

I like how you constructed your table, especially by adding who did each measurement
At some point, your group will need to determine the average and the standard deviation for each pippette.
Don't forget to fill in what you did on Friday. You can leave Wednesday blank since you were absent.


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