Lab 6 – Determination of the Dye Concentration in A

Lab 6 – Determination of the Dye Concentration in A Powerade Drink C H M 2 0 4 5 L – D r. Y a v u z P e t r o w s k i The statement is: “I cer fy that this is my own work and I understand that if I am found to be in viola on of the honor code, I will be subject to the highest penalty” Name: Jetzebell Callens Znumber: 23744291 PRELAB Background: Please complete the following sec ons. Purpose of the experiment: In your own words, the purpose of the experiment including a brief descrip on of the lab and the reason for doing the experiment (what we are trying to determine and how we will go about determining it). Explain the concepts we are inves ga ng; explain why and how they are useful, and how those concepts apply to the experiment; show relevant equa ons if you need to. The purpose of this experiment is to investigate the relationship between the concentration of copper(II) sulfate (CuSO₄) solutions and their absorbance using a spectrophotometer. We aim to determine how changes in concentration affect the amount of light absorbed by the solution, which is crucial for applications in chemistry and biology. In this lab, we will prepare a series of CuSO₄ solutions with known concentrations and measure their absorbance at a speci c wavelength using a spectrophotometer. By applying the Beer-Lambert Law, which states A=ϵcl (where A is absorbance, ϵ is the molar absorptivity, c is concentration, and l is the path length), we can quantify the concentration of unknown solutions based on their absorbance readings. ti ti ti ti ti ti ti fi fi Understanding this relationship is important because it allows us to accurately determine the concentration of substances in various elds, such as environmental monitoring and pharmaceutical analysis. By plotting a standard curve with known concentrations, we can interpolate the concentration of unknown samples from their absorbance values, making this method a powerful analytical tool. Get premade copper sulfate solution in graduated solution in volumetric ask and carryout a series of ve dilution add each solution and water to test tubes and mix the solution. fl fl fl spectrophotometer. Put rst cuvette in slot. ti Using a pipet ll up cuvettes about ¾ height full with each of the solutions including the Powerade drink solution Record exact wavelength from the tt The absorbance reading should be between 0.00 and 1.0. calculate molar concentration fl fl tt fi fl fi fi Draw a calibration graph of absorbance Using the table calculate the amount of copper sulfate solution and obtain the calculated amount fl Get 10mL of the Powerade drink mix and put in a volumetric ask. Set the solution aside and get unknown solution 10mL graduated pipet and ve smaller volumetric asks fi fl fl Flow Chart: Complete the experimental procedure for this experiment by using the informa on provided in the power point and 360 experimental videos in a ow diagram format. A ow chart indicates the procedure of how the experiment is performed. The ow chart must be wri en in the correct ow chart format (box and arrow). Handwri en ow charts are not accepted. See the example of the ow chart in the canvas module. Waste Collec on: Type out the chemicals used in this experiment, their hazards if applicable, and any other safety concerns associated with this experiment. You can search for the Materials Safety Data Sheet document on the internet to list hazards and safety concerns. You can add an extra row if you need extra space. Chemicals Safety Hazard CuSO4 Skin and eye irrita on H2O No Hazard DATA PROCESS Table: Fill out the following table by using the data collected through virtual 360 Lab. The concentra on of unknown solu on must be calculated by using Beer-Lambert calibra on curve and equa on of line. Solu on Volume of CuSO4 Solu on, mL Volume of DI Water, mL Absorbance (at 630 nm) Concentra on in M 1 2.00 mL 8.00 mL 0.222 0.08 2 4.00 mL 6.00 mL 0.383 0.16 3 6.00 mL 4.00 mL 0.527 0.24 4 8.00 mL 2.00 mL 0.709 0.32 5 10.00 mL 0.00 mL 0.838 0.40 Powerade Solu on 0.556 From equa on of line Calibra on Curve Y=2.1807x 0.9972 Data Processing 1. Calculate the molar concentra ons of the diluted solu ons and record them on your data sheet. Please use ti ti ti ti ti ti ti ti ti ti ti ti ti ti ti ti ti ti dilu on formula for this calcula on: M1 xV1 =M2 x V2 (concentra on of the CuSO4 stock solu on is 0.400 M) 2. Using Excel prepare a plot of the absorbance versus CuSO4 concentra on. Pay a en on to the graphing rules. 3. Determina on of the unknown concentra on: a. Determine the concentra on of the Powerade solu on from the excel graph by using equa on of line. b. Determine the concentra on of the Powerade solu on by using calibra on curve. By using the absorbance of the unknown and marking a straight line from the y-axis to the curve then a straight line from the curve to the x-axis. 4. Complete discussion ques ons. CALCULATIONS: Show (type in the table) your calcula ons for molarity. YOU MUST SHOW ALL YOUR CALCULATIONS TO RECEIVE CREDIT FOR THEM! Proper use of signi cant gures and units is part of the grading. Calcula ons: Show Your Calcula ons in Table Provided: Solu on Volume of CuSO4 Solu on, mL Volume of DI Water, mL Concentra on Calcula ons, M 8.00 mL 0.400M) (2.00mL)=M2(10.00mL) 1 2.00(0.400M) (2.00mL)/(10.00mL) 2.00 0.08 2 6.00 mL 0.400M) (4.00mL)=M2(10.00mL) 4.00(0.400M) (4.00mL)/(10.00mL) 0.16 4.00 mL (0.400M) (6.00mL)=M2(10.00mL) 6.00(0.400M) (6.00mL)/(10.00mL) 0.24 2.00 mL (0.400M) (8.00mL)=M2(10.00mL) 8.00(0.400M) (8.00mL)/(10.00mL) 0.32 0.00 mL 0.400 M 4.00 3 6.00 4 8.00 5 10.00 Powerade Solu on From equa on of line: Y=2.1807x From Calibra on Curve: 0.9972 Excel Graph: ti ti tt ti ti ti fi ti fi ti ti ti ti ti ti ti ti ti ti ti ti ti ti ti ti Direc ons for Excel Graph 1. Use your data table and type concentra on and absorbance data into an Excel document, only type numbers, and do not include units in the data area of your excel table. Start typing concentra on into cell A1, absorbance into cell B1, and so on. Start tying the numerical data into the second row and con nue un l the en re data is copied. 2. Select all data by clicking on the cell, and then dragging over and down to the last cell that data is wri en. 3. On the Excel window, nd the menu item tled “insert” and in the “Charts” area click on the “Insert Sca er (X, Y)” bu on. A basic graph with data set should appear. 4. Edit your graph so that it contains the correct forma ng components, you need a tle describes the study under and labels for your x- and y- axes together with units such as unit for x axis. o To add chart components such as x and y labels, click on the top right corner of the graph, then click the menu item in the Windows ribbon tled “Chart Design”. In that menu, click on the “Add Chart Element” and select “Chart Title” and both op ons under “Axis Titles. You can edit the text by clicking or doubleclicking on the text in the graph and typing. 5. Right click on any of the data points and select “add trend line”. The “Format Trend line” menu that appears to the right of the window, make sure “Linear” is selected. In this same menu, click on “Set Intercept to = 0” and click on “Display equa on on chart” 6. Find the concentra on from equa on of line. 7. Find the concentra on from excel graph, mark on the graph. tt tt ti ti ti ti ti tti ti ti ti ti ti fi ti ti ti tt 8. Do not forget to save your Excel sheet and copy a screenshot of your graph into the space given. GRAPH CONSIDERATION FOR DISCUSSION & CONCLUSION As you write your discussion and conclusion paragraphs for the discussion assay, here are some ps and ques ons you should answer. These are in addi on to the "Guidelines for a good discussion and conclusion" document in the introduc on module. • Purpose of the experiment. • What is a spectrophotometer, and how is it u lized in this experiment? • What is the Beer-Lambert Law, and how is it related to absorbance and concentra on? • What is dilu on, and why CuSO4 solu on need to be diluted? • How is the concentra on calculated from absorbance readings using the Beer-Lambert Law? • What is the process for plo ng a standard curve, and how is it used to analyze unknown solu on? • Conclusion statement: Was this a good experiment to use to support your purpose and why? DISCUSSION & CONCLUSION ASSAY The purpose of this experiment was to explore the relationship between the concentration of copper(II) sulfate (CuSO₄) and its absorbance using a spectrophotometer. This instrument measures light intensity at speci c wavelengths, helping us determine how absorbance changes with concentration. The Beer-Lambert Law relates absorbance (A) to concentration (C) and path length (l) with the equation A = ϵcl. It states that absorbance is directly proportional to concentration, allowing us to derive concentration from measured absorbance values. Dilution reduces a solution's concentration by adding solvent. In this case, CuSO₄ needed dilution to ensure absorbance readings were within the spectrophotometer's measurable range. To calculate concentration from absorbance, we used the Beer-Lambert Law. By measuring the absorbance of diluted solutions, we could use a standard curve to determine unknown concentrations. ti ti ti ti ti ti fi tti ti ti ti ti Plotting a standard curve involves measuring the absorbance of known CuSO₄ concentrations and graphing these values. This curve helps analyze unknown solutions by allowing us to interpolate their concentrations based on absorbance.