- Paragraph Styles Editing Voile Senutno Analysis Of Com By Spectrophotometry Use Proper Sigficant Figures Throughout The 1 (38.89 KiB) Viewed 43 times
- Paragraph Styles Editing Voile Senutno Analysis Of Com By Spectrophotometry Use Proper Sigficant Figures Throughout The 2 (28.74 KiB) Viewed 43 times
- Paragraph Styles Editing Voile Senutno Analysis Of Com By Spectrophotometry Use Proper Sigficant Figures Throughout The 3 (28.12 KiB) Viewed 43 times
- Paragraph Styles Editing Voile Senutno Analysis Of Com By Spectrophotometry Use Proper Sigficant Figures Throughout The 4 (39.7 KiB) Viewed 43 times
- Paragraph Styles Editing Voile Senutno Analysis Of Com By Spectrophotometry Use Proper Sigficant Figures Throughout The 5 (30.03 KiB) Viewed 43 times
- Paragraph Styles Editing Voile Senutno Analysis Of Com By Spectrophotometry Use Proper Sigficant Figures Throughout The 6 (14.46 KiB) Viewed 43 times
Paragraph Styles Editing VOILE Senutno Analysis of Com* by Spectrophotometry Use proper sigficant figures throughout the exam . This exam involves using absorbance spectrum to analyze a Co" unknown solution. Multiple working standard solutions will be prepared by diluting a stock solution of Cock, The 0.200M stock solution will be the highest concentration standard; it has been analyzed to give the table (below) of absorbances as a function of wavelength. This analysis will be done by spectrophotometry. Measurements are done in 1.20cm cuvettes. The stock solution, glassware, and the spectrophotometer are provided. Everything else is your responsibility. Submit your answers onto blackboard, Wavelength Absorbance () 400 0.026 420 0.130 440 0.233 460 0.414 480 0.672 500 0.843 520 0.918 540 0.704 560 0.374 580 0.172 600 0104 Plot en absorption spectrum. Submit the graph to this exam, following this sheet of paper. You can use excel to create this graph. Locate the wavelength value of maximum absorbance. Indicate this wavelength on the graph and record the value below. Sms = 520 num From the absorption spectrum, calculate the value of the molar absorptivity coefficient for the solution 3.825 (5)
Editing 580 600 620 640 0.172 0.104 0.078 0.050 From the absorption spectrum, calculate the value of the molar absorptivity coefficient for the solution 3.825 (5) 1 If you change the concentration of the solution above, will the molar absorption coefficient change? Why? (5) No, if you change the concentration of the solution the molar absorption coefficient does not change.
Dilutions for the lab. For this lab you need to create five dilutions. In the chart below, I have provided you with the five dilution concentrations. To create the dilutions, you are provided with 50.0 mL of 0.200M cobalt chloride stock solution. Use your beers law equation to help answer the data table below. Fill in the missing information. Show your work. Solution: 0.180m/0.200m=0.9 I 0.918*0.900=0.826 Dilution Concentration (M) Absorbance for each solution 0.180 0.150 0.120 0.0900 0.0600 0.826 0.689 0.551 0.413 0.275 Use the concentrations and absorbance in the above chart, in the chart on page 3 also.
Unknown Concentration and Absorbance: At the end of the lab, you will find your unknown information. Use this information to find your specific unknown absorbance. Record the information in the space below. Use the sample dilutions, from above (page 2), to calculate a known beer's law graph. Record your concentrations and their absorbances below. Absorbance Solution Concentration OM (blank) 10.180 Create a graph comparing the known solution concentration and absorbance. Use this graph to calculate the Unknown concentration (C#1). Attach your graph on blackboard. (10) 0.150 Unknown code: 51 0.120 I A(from table on last page) = 0.0900 0.0600 C #1 When finished, all your working standard solutions are to be placed in the waste container. Perform the best linear regression using Graphing calculator or Excel and report your regression equation in terms of the variables studied. Include the value of R2. (5) Equation RP
OM (blank) 10.180 your graph on blackboard. (10) 0.150 Unknown code: 51 0.120 A[from table on last page) = 0.0900 0.0600 C #1 When finished, all your working standard solutions are to be placed in the waste container. Perform the best linear regression using Graphing calculator or Excel and report your regression equation in terms of the variables studied. Include the value of R?, (5) Equation R I Using your regression equation, calculate the concentration of your unknown. Show your calculation below (5)
C#2= Using your regression equation, Beer's Law, and only necessary information that is common to all your frials, calculate the value of the molar absorption coefficient. Show your calculation I Conclusion: During your calculations did you recognize any type of errorProvide reasoning why