Module #2 Post-Lab Question Submission

A liquid sample was analyzed for Fe³+. A plot of absorbance (y-axis) vs. concentration (ppm; x-axis) of the external standards produced a calibration line with an equation y = 0.2256x -0.0903 (R² = 0.9973). The absorbance of the sample was 1.25. Determine the amount of Fe³+ in the sample (in ppm).

The absorbance of an unknown dye solution is measured to be 1.06 by a spectrometer. The calibration plot of the spectrometer is provided below. What is the molar concentration of the unknown sample (in mole L)? Absorbance vs. Molarity 18 y3 67024x-0.0343 16 14 12 1 0.8 0.6 0.4 0.2 01 0.2 0.000005 00001 0000015 Concentration of solutions, mol/L 0.00002 0.000025 000003 0 163e-5 O 2.35e-6 0 163 0 235 Absorbance

Consider the reaction : A+B 2 AB. A calibration plot was constructed using x as the concentration for AB in M and y as the absorbance value of AB, it provided the linear equation : y=25x+0.0008. Determine the concentration of AB in M if the absorbance value is 1.22. Round and report your value to the THIRD decimal place. Numeric value only, no unit. No new data to sa IMG 0915.jpeg e to search PrtScn Home

urses/ 2951 2. A linear standard curve of KMnO4 is prepared from a set of standard solutions by plotting absorbance (y) vs. concentration (x). Use Logger Pro (as described in the Data Analysis for this experiment), or Google Sheets/Excel, to plot this standard curve using the data in Table 1. Help with spreadsheets [PDF] Table 1: Data for the standard curve of KMnO4 Absorbance Concentration (M) 0.372 6.00 x 10-4 0.298 0.223 0.149 0.0744 After plotting the standard curve, enter its slope below (not the equation of the line). Report your answer to 3 significant figures. If your answer ends in one or more zeros, use scientific notation. Slope = 4.80 x 10-4 3.60 x 10-4 2.40 x 10-4 1.20 x 10-4 M-1 M 3. Suppose that an unknown sample is analyzed spectrophotometrically at the same wavelength that was used for the standard curve and the absorbance was found to be 0.186. Use the standard curve to find the concentration of the unknown. Hint:

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

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 = 4.943x + -0.0001 The absorbance of a solution of unknown concentration is determined to be 0.48. Calculate the concentration of the unknown solution in M. Give your answer to three decimal places.

In spectrophotometric analysis, the relationship between the absorbance A and the analyte's concentration C is: A = ebC + Ablank What is the molar extinction coefficient I and its absolute uncertainty if A is 0.68 ± 0.06; Ablank is 0.06 ± 0.01; b is 1.00 cm; and C is (0.45 ± 0.03)x10-5 mol/L?

A student prepared four standard solutions of (NH4)2Fe(SO4)2 and measured their absorbance at 505 nm.  She created a calibration plot with the best-fit line of y = 9372 x + 0.0539.  She measured the absorbance of her diluted unknown sample solution as (4.69x10^-1) nm.  If she prepared her diluted sample solution by diluting 10.00 mL of the original solution to a total volume of 50.00 mL with deionized water, what is the concentration of Fe2+ in her original solution?  Answer in units of M. Note: Your answer is assumed to be reduced to the highest power possible.

Chemistry   0.1237 (±0.0001) g of sodium carbonate (Na2CO3) required 22.46 (±0.02) cm3 of aqueous HCl for complete neutralisation. Determine the concentration of the HCl in mol dm–3 together with its uncertainty in mol dm–3 to an appropriate number of digits. You may assume the error in the molar mass of Na2CO3 is negligible.

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?

AP Questions // Questions 10 - 11) A student creates four solutions with varying concentration of FeSCN2 and gathers the following data at 298 K using a spectrophotometer calibrated to 460 nm: [FESCN] Absorbance 1.1 x 10-4 M 0.076 1.6 x 10-4 M 0.112 2.2 x 10-4 M 0.167 2.5 x 10-4 M 0.199 On the axis below, create a Beer's Law calibration plot for [FESCN2*]. Draw a best-fit line through your data points.

In a Bradford assay, 11 µl of a protein isolate sample was diluted by adding 21 µl of water prior to the addition 2.0 mL Bradford reagent. Calculate the protein concentration (in mg/mL) of the original protein isolate sample whose absorbance reading at 595 nm is 0.304 after dilution. The protein standard solutions used for the calibration curve of the Bradford assay was constructed using bovine serum albumin (BSA) stock solution whose concentration is 200 µg/mL. The concentration and the corresponding absorbance reading at 595 nm of the protein standard solutions are summarized in the table below: Standard soln # 1 2 13 4 6 conc of BSA 12.00 24.00 36.00 48.00 60.00 (pg/mL) Absorbance at 595 nm 0.000 0.156 0.249 0.328 0.411 0.528 zNote: Final answer format must be x.xxx (three decimal places). Round off only in the final answer. Do not round off in the middle of the calculation.

How to solve the following?

Calculate the equilibrium concentration of FeSCN^2 Please explain.

= 1 5 Absorbance vs. Concentration y = 0.2755x 0.2- 0.1- 1.400 2.000 1.800 1.600 1.000 0.200 1.200 0.400 0.600 Concentration (M) Using the calibration curve, calculate the molar concentration for a solution with a measured absorbance of 0.374. Round your answer to 3 significant digits Concentration = M X Sub Absorbance 0.7- 0.6- 0.5 0.4- 0.800

The trendline for a calibration curve is y=4.299x+-0.0001. The absorbance of a solution of the unknown concentration is 0.0812 What is the concentration of the unknown solution in uM

Using the data below, please create a calibration graph and determine the concentration of the unknown sample. Standard #1 Standard #2 Standard #3 Unknown sample Concentration 1.5 x 10 M 2.0 x 103 M 2.5 x 10 M ? Absorbance 0.61 0.80 0.98 0.72 a) 1.6 x 10 M b) 1.8 x 10° M c) 2.1 x 103M d) 2.2 x 10 M

Concentration Fe(SCN)2+ (M) Absorbance 0.0001 0.386 0.0002 0.774 0.0003 1.154 0.0004 1.527 0.0005 1.931 Question 2 Analysis Section 1 1. Open a spreadsheet program, like Excel or Desmos, and plot your data points, with Absorbance on the y-axis and Concentration on the x-axis. 2. Fit a linear trendline and make sure the equation is labeled on your graph, including the R² value. 3. Fill in your equation below. Absorbance = -Concentration + The slope of your equation gives you the s-1 in the Beer's law equation: A = scl. Since I = 1 cm, the slope is equal to the ɛ of Fe(SCN)2+. The units of & are 1/(M*cm).