The light absorbance A of a molecule in solution is measured as a function of concentration [X]. [X]/M                             A                            0                                     0 1.0 × 10–4                      0.157 3.0 × 10–4                      0.482 5.0 × 10–4                      0.713 7.0 × 10–4                      1.15 9.0 × 10–4                      1.37 Use spreadsheet software to graph the data and calculate a best–fit linear trendline. What is the equation of the line that best fits the data?   Question 5 options:   A = (1.55 × 103 M–1) [X] + (4.93 × 10–4)   A = (1.13 × 103 M–1) [X] + (2.52 × 10–4)   A = (9.94 × 102 M–1) [X] + (3.81 × 10–4)

Table 2: Absorbance Values of Standards and Unknowns. Sample Blank Standard Solution 1 Standard Solution 2 Standard Solution 3 Standard Solution 4 Standard Solution 5 Water Sample 1 Water Sample 2 Phosphate Concentration (in ppm) Y17 0 ppm 0.02 ppm 0.04 ppm 0.08 ppm 0.16 ppm 0.32 ppm Freeman Lake 0.001 0.325 0.292 0.413 0.315 0.039 0.054 0.049 Absorbance at 2= 690 nm Calculations: 1. Construct a phosphate standard curve in Excel by plotting concentration (in ppm) on your x-axis and Absorbance (unitless) on your y-axis for your known solutions. Label the axes on the graph and provide the curve with a title. Use a linear trendline to generate a best fit line to your data. Label the graph with the equation and the R" value. Insert your labeled graph in the space below. X

concentration of unknown yellow dye (uM)

To test a spectrophotometer’s accuracy, a solution of 60.06 ppm K2Cr2O7 is prepared and analyzed. This solution has an expected absorbance of 0.641 at 350.0 nm. Several aliquots of the solution produce the following absorbance values.   0.640    0.638    0.640    0.639    0.640    0.639    0.638  is there any significant difference between the experimental mean and the expected value at a 99.9% confidence level?   Question 21 options:   Yes because tcal<tcritical   Yes because tcal>tcritical   No because tcal<tcritical   No because tcal>tcritical

The best fit curve line to an absorbance vs. concentration plot for standard solutions of a dye has a slope of 0.1815 mL/mg and intercept of 0.0477. A sample solution prepared of the same dye has an absorbance of 0.464 at the wavelength used to establish the Beer's law plot. What is the concentration of dye in the prepared solution? Select one: O a. 0.132 mg/mL b. 2.29 mg/mL O c. 0.464 mg/mL O d. 2.82 mg/mL e. 0.0365 mg/mL Next page Law Tutorial Part 2 Jump to... Exp #9 - Laboratory Practical► Worksheet étv A

After determining the absorbance of several standards of known concentration, the trendline for a calibration curve (AKA a standard curve) plotting absorbance (y-axis) against concentration (M, x-axis) is determined to be y = 4.586x + -0.0010 %3D The absorbance of a solution of unknown concentration is determined to be 0.68. Calculate the concentration of the unknown solution in M. Give your answer to thrėe decimal places.

Calculate the concentration of unknown red dye solution

1. Data & Results 4.0 mglmL Concentration of stock solution (include units): Table 1-Beer's Law Plot Data V Volume of standard solution dispensed (mL) M, Diluted concentration (include units) Sample Absorbance A 2.00 mL 0.084 4.00 mL 0.173 l6.00 mL 0.259 8.00 mL 0.340 E 10.00 mL 0.418 Equation of trendline from Beer's Law plot: whats the diluted concentration and equation of trendline from the beers law plot once created?

Table 1.0 of data showing calibration standards prepared by dilution and the absorbance Concentration CuSO4 (M) Volume of 0.5M (ml) Volume of D/Water (ml) Absorbance 0.00 0.10 0.20 0.30 0.40 0.50 II. 0.00 1.00 2.00 3.00 4.00 5.00 5.00 4.00 3.00 2.00 1.00 0.00 1. Construct a graph of concentration against absorbance, clearly show a best fit line. Find regression of your graph. Show how 0.000 0.406 0.638 0.854 1.202 1.276

To determine the molar concentration of a metal ion in a solution of unknown concentration, a student fırst made five standard solutions that contain the metal ion of interest and measured the absorbance of each solution in a spectrophotometer at its Amax- A calibration curve was obtained that had an equation of y = 5.747 x + 0.013 Next, the student pipetted 15.0 mL of the initial solution of unknown concentration into a 100.0 mL volumetric flask, and filled the flask with deionized water to the line. The absorbance of this final diluted solution was found to be A = 0.226 at Amax. The color of the original and diluted solution was blue. What is the molarity of the original solution, as well as an approximate Amax for this metal ion? 2max = 599 nm and concentration is 0.247 M Amax 457 nm and concentration is 0.247 M %3D 2 max = 457 nm and concentration is 0.0371 M 1 max 599 nm and concentration is 0.0371 M Amax = 599 nm and concentration is 0.00557 M