Environmental Engineering Lab Report
I need a lab Report on this Experiment.Please no Plagiarism or copy from other source.I upload to file an example lab report to help and the data for the experiment.
lab5_data.pdf
lab5_example.docx
Unformatted Attachment Preview
Scanned with CamScanner
Scanned with CamScanner
Scanned with CamScanner
Scanned with CamScanner
Scanned with CamScanner
Scanned with CamScanner
1. UV-Vis Spectroscopy
1.1
Introduction
Objective
Review basic analytical chemistry skills, including solution making, transferring and linear
diluting. Understand the error involved and error propagation.
Materials:
Methylene Blue C16H18ClN3S, MW 319.85.Also called Swiss blue. One gram dissolves in about
1000 ml of water. Peak absorption at 369 nm
1.2
Create Calibration Curve from standard solutions
Procedures:
1.
2.
3.
4.
5.
Weigh 500mg dye on electric balance
Dissolving all the solid dye in beaker
Transfer all the solution into a 500ml volumetric flask
Fill up the volumetric flask to the tick mark
Prepare standard solutions of 500, 200, 100, 50 and 20 ppm from 1000 ppm stock solution
Table 1-1 Preparation of standard solutions
STD
PPM
Stock
DI water
Total Volume
20
0.2
9.8
10ml
50
0.5
9.5
10ml
100
1
9
10ml
200
2
8
10ml
500
5
5
10ml
6. Vortex vial to complete mix
7. Transfer Standard solutions to cuvette
8. Measure the transmissivity at a peak measure three times and make a note of your
results in your lab notebook
9. Create calibration curves from data.
Table 1-2 Absorbance of standard solutions
PPM
Wavelength
1
Absorbance
2
Average
20
50
100
200
500
UV/VIS
Absorbance
1
0.8
0.6
0.4
0.2
0
0
50
100
150
200
250
300
Concentration (ppm)
350
400
450
500
Figure 1-1 Calibration curve from standard solutions
5.3 Two steps of a serial dilution and measure the concentrations of unknown
samples
1. Pour about 11 ml unknown concentration of methylene blue solution from the bottle to
your vial
2. Dilute the dye solution 10 fold by using pipettes : Pipette 1 ml above sample solution to
your vial
3. Fill the solution to 10 ml
4. Transfer Standard solutions to cuvette
2
5. Measure absorbance of each
Figure 1-2 Serial Dilution of unknown samples
Table 1-3 Absorbance of unknown samples
Absorbance
Serial
Dilution
1
1/10
Sample 1
Sample 2
Sample 3
1/100
Wavelength
Instrument Use
1. Power on instrument (switch is on left side).
2. Turn on monitor and double-click Cary win UV
3. Instrument will run through a start-up check for about 1 minutes.
4. In the toolbar frame, select the Concentration icon.
5. In dialog box, enter wavelength 369 nm.
a. Choose Abs (absorbance).
b. Replicate is 2
6. Click on Standard.
a. unit : mg/L
b. number of standard and concentration of standard solution
7. Click on Sample and enter sample number
8. Click OK
9. Click on Zero icon after insert Blank cuvette into UV slot.
10. Fill cuvette ¾ with standard samples and cleaning cuvette surface with chem wipes.
11. Place cuvette in the slot.
12. Click Start
13. Record Abs(absorbance)
14. Drawing standard graph
15. Fill cuvette ¾ with unknown samples and cleaning cuvette surface with chem wipes.
3
16. Place cuvette in the slot.
17. Click Start
18. Record concentrations
Lab report requirement
o Calculate solution concentration by ppm for all solutions
o Discuss source of data errors
o How do you improve your skill to get better accuracy and precision of solution making
o Describe the key steps of the experiment
o Attach all the original data and spectrum
4
…
Purchase answer to see full
attachment
