HFCC Spectroscopy Molecular Geomtery Freezing Point Depression Lab 3 to 8 Report 3 lab procedures; 1 due tomorrow, the rest a couple days after. summarized

HFCC Spectroscopy Molecular Geomtery Freezing Point Depression Lab 3 to 8 Report 3 lab procedures; 1 due tomorrow, the rest a couple days after. summarized each in one page

lab 3 ; solutions and spectroscopy

lab 6; molecular geomtery (Send after u accpet)

lab 8; freezing point depression (after) LAB PROCEDURE
Please print the worksheet for this lab. You will need this sheet to record your data.
Download Worksheet
Part A: Determination of the Concentration of a Copper(II) lon Solution
1 A spectrophotometer will be set up in your work area. Make sure is turned on and allow it to warm up.
2
While the spectrophotometer is warming up, obtain two serological pipets, and set up a beaker for waste Cu2+ solution.
3
Obtain about 15 mL stock Cu2+ solution. Write its exact concentration in Data Table A.
4
Once the spectrophotometer is warmed up, take a blank spectrum of deionized water in a vial as described in the MicroLab
spectrophotometer instructions provided in lab.
5
Condition the pipet you will be using for the Cu2+ solution as shown in the pipet video under instrumentation and as described in the
Volumetric Glassware section of the Introductory Material of this lab manual. Dispense the required volumes of Cu2+ solution (1.2 mL)
and deionized water (4.8 mL) for Solution 1 into a test tube and record your volumes in Data Table A.
Be careful while doing this, the pipets may be tricky to handle at first.
.
Record volumes to 0.01 mL with some uncertainty in the last digit.
6
Stopper the test tube and mix the solution well by inverting a couple of times.
7
To condition your vial, carefully pour a small amount of the solution you just prepared into a vial and pour it out to waste.
8
Refill the vial with solution and take an absorbance spectrum. Identify the wavelength of maximum absorbance near 600 nm. Record the
wavelength and absorbance at this wavelength in Data Table A. Absorbance values are reported to the 0.001. For all remaining
absorbance measurements in this experiment, be sure to use the same wavelength you have identified as the maximum.
9
Record the concentration of Cu2+ in Solution 1 in Data Table A.
Record the concentration of Cu
in Solution 1 in Data Table A.
10 Retain the sample in the vial until you have completed your calibration plot. Students often choose to label a sheet of paper with
positions 1, 2, 3 and 4, placing each vial on the appropriate position.
11
Following steps 5 – 10, prepare Solutions 2 – 4, measure their absorbances and calculate the Cu2+ concentration in each. Record these
in Data Table A. Do not close the MicroLab file, as this calibration curve will be used to determine the concentrations in Part B.
12
The MicroLab software will plot the absorbance of the Cu2+ solutions that you made as a function of their concentrations. The trendline
and R2 value are displayed. If your plot is linear with an R2 value of 0.9 or greater, continue the experiment. If your R2 value is low,
consult with your lab instructor.
13 Safely dispose of the calibration solutions in your copper waste beaker.
14 Obtain a couple of milliliters of unknown solution and record the number of your solution in Data Table A.
15
Condition a vial with the unknown Cu2+ solution and refill with unknown Cu2+ solution. Measure the absorbance of the unknown Cu2+
solution and record it in Data Table A.
Part B: Preparation of a Copper(ll) Ion Solution from Solid CuSO4.5 H20
1
Carefully weigh the desired amount of CuSO4.5 H20 on a weighing paper or in a small beaker as shown in the Using an Analytical
Balance video under Instructional Videos and as described in the Analytical Balance section of the Lab Equipment of this lab
manual. Record the exact amount that you used in Data Table B.
2
Transfer the CuSO4.5H20 into a 25.00 mL volumetric flask and dilute to the mark with deionized water as shown in the volumetric
Flask video under Instrumentation and described in the Volumetric Glassware section of in the Introductory Material of this lab manual.
3
After the solution is well mixed, condition a vial with it. Then refill the vial, measure and record the absorbance of your solution nm in
Data Table B.
Part C: Preparation of a Copper(ll) Ion Solution by Dilution of a Stock CuSO4 Solution.
1
Record the exact concentration of the stock copper(II) solution in Data Table C.
2
In a small, clean beaker, obtain a little more of the stock copper(II) solution than you calculated in Question 6.
Part C: Preparation of a Copper(II) Ion Solution by Dilution of a Stock CuSO4 Solution.
1
Record the exact concentration of the stock copper(II) solution in Data Table C.
2
In a small, clean beaker, obtain a little more of the stock copper(II) solution than you calculated in Question 6.
3
First condition a serological pipet, then use it to transfer the volume of copper(II) solution you calculated into a 25.00 mL volumetric
flask. Record the exact amount that you transferred in Data Table C. Dilute to the mark with deionized water.
4
After the solution is well mixed, condition a vial with it. Then refill the vial, measure and record the absorbance of your solution in Data
Table C.
5
When you are finished taking measurements, collect all your copper solution waste and place it in the waste bottle in the lab, making
sure not to overfill it. Rinse and dry all your glassware with water and return it to the set-up area where you found it. Close the MicroLab
software.
6
Remember to show your TA your calibration curve and measured [Cu2+] concentration of your solutions for Part B and Part C. Your TA
will manually grade the results and enter your score into WebAssign.
7
Before leaving, enter your results in the In-Lab assignment. If all results are scored as correct, log out. If not all results are correct, try to
find the error or consult with your lab instructor. When all results are correct, note them and log out of WebAssign. The In-Lab
assignment must be completed by the end of the lab period. If additional time is required, please consult with your lab instructor.
Copyright © 2011 Advanced Instructional Systems, Inc. and North Carolina State University | Credits

Purchase answer to see full
attachment