Copper-Iron Final Analysis

A series of standard iron-phenanthroline [Fe(phen)3]2+ complex ion solutions were prepared. The absorbance of each solution was measured at a wavelength of 510 mm. A calibration curve of absorbance vs. concentration was then plotted to obtain a linear equation of y = 0.0018x+0.0749. The absorbance of an unknown [Felphenly solution was measured to be 0.326. Calculate the concentration of the complex ion. NOTE! Report your answer as a WHOLE #. Type your answer...

A student makes a Beer's Law plot of A vs [Fe(SCN)2+] in the first part of the equilibrium constant lab, and gets the following information from the trendline. y = 50.7x R² = 0.9999 If the student measures a absorbance of 0.167 for a solution in the second part of the lab, what equilibrium concentration of [Fe(SCN)²+ would be reported?

1. A student collects the following data for the absorbance of a complex measured in 1.00 cm spectrophotometric cells. The molar absorptivity (ɛ) of the complex under investigation is 0.750 L/mol·cm. Calculate the concentration of the solution at each time of the reaction. Measured Complex Concentration Time (min) Absorbance (M) 0.000 1.500 10.000 1.313 20.000 1.125 30.000 0.938 40.000 0.750

The sodiuṁ salt of 2-quinizarinsulfonic acid (NaQ) forms a complex with Al3+ that absorbs strongly at 560 nm. From the data of the absorbance, find formula of the complex. In all solutions, [A3+]=3.7x105 M and the cell length is 1.00 cm. (Apply the molar-ratio method.) ca/M A(560) mol ratio [Al3+]/[Q] 1,00E-05 0,131 2,00E-05 0,265 3,00E-05 0,396 4,00E-05 0,468 5,00E-05 0,487 6,00E-05 0,498 8,00E-05 0,499 1,00E-04 0,5 OH NaQ

The absorption spectra of solutions containing Br2 are solvent dependent. When elemental bromine is dissolved in nonpolar solvents such as hexane, a single absorption band in the visible spectrum is observed near 500 nm. When Br2 is dissolved in methanol, however, this absorption band shifts and a new band is formed. Account for the appearance of the new band. Is the 500 nm band likely to shift to a longer or shorter wavelength in methanol? Why?

You are trying to develop a field instrument to do nitrate analysis based on the formation of an aqueous colored complex which has a λmax at 814 nm.  Describe the spectrophotometer that would work best for this type of study.  Include all major parts of the spectrophotometer, how they are arranged, and the type of detector that could be used.

The concentration of Fe2+ in a sample is determined by measuring the absorbance of its complex with ferroxine. The sample, measured in a 1.00 cm cuvette, has an absorbance of 0.254. The reagent blank in the same cuvette has an absorbance of 0.015. What would be the absorbance reading for each of these two solutions if measured in a 7.00 cm cuvette? Asample = Areagent blank =

The red color of soil is often due to the presence of iron. Metal ions are extracted from soil by stirring the soil in acid and then filtering the solution. One method for the analysis of Fe2+ is to form the highly colored Fe2+–thioglycolic acid complex. The complex absorbs strongly at 535 nm. Calibration standards of 1.00, 2.00, 3.00, 4.00, and 5.00 ppm are prepared by transferring appropriate amounts of a 10.0 ppm working solution of Fe2+ into separate 50-mL volumetric flasks, each of which contains 5 mL of thioglycolic acid, 2 mL of 20% w/v ammonium citrate, and 5 mL of 0.22 M NH3. After diluting to volume and mixing, the absorbances of the standards are measured.   a)Use the data table below to prepare a calibration curve (absorbance versus concentration in ppm). Fit the data to straight line and find the equation for the straight line and the R2 value. (Hint: Think about what to do with the absorbance of the blank.)

The red color of soil is often due to the presence of iron. Metal ions are extracted from soil by stirring the soil in acid and then filtering the solution. One method for the analysis of Fe2+ is to form the highly colored Fe2+–thioglycolic acid complex. The complex absorbs strongly at 535 nm. Calibration standards of 1.00, 2.00, 3.00, 4.00, and 5.00 ppm are prepared by transferring appropriate amounts of a 10.0 ppm working solution of Fe2+ into separate 50-mL volumetric flasks, each of which contains 5 mL of thioglycolic acid, 2 mL of 20% w/v ammonium citrate, and 5 mL of 0.22 M NH3. After diluting to volume and mixing, the absorbances of the standards are measured. a)What is the effect on the reported concentration of iron in the sample if there is a trace impurity of Fe2+in the ammonium citrate?

Briefly explain how AAS can quantify the amount of lead in sample solution?

. A student collects the following data for the absorbance of a complex measured in 1.00 cmspectrophotometric cells. The molar absorptivity (ε) of the complex under investigation is 2.25×103L/mol·cm. Calculate the concentration of the complex in solution at each time of the reaction.Time (min)MeasuredAbsorbanceComplex Concentration(M)0.000 1.50010.000 1.31320.000 1.12530.000 0.93840.000 0.750

Describe the application of AAS (Atomic Absorption Spectrophotometry) analytical methods for gold, copper and iron ore deposit evaluation which involve surface and subsurface geochemical sampling in a tropical environment.

1) A Chem 102 Student prepared a cobalt coordination compound. Parts "a-c" refer to this problem. a) Next, she analyzed the cobalt content of the compound by preparing a series of known concentration cobalt solutions and prepared a Beer's law graph of absorbance (Y) versus concentration(X). The equation of the line was determined using Excel to be: Y=7.50 X the coordination compound and ultimately diluted it to a total volume of 100.0 mL and measured its absorbance to be 0.310. Calculate the percent cobalt (by mass) in the compound. Where X is concentration in Molarity. She weighed 1.1050 g of

The absorbance of iron is determined at 508 nm. From the information given in the laboratory handout, what do you think the visible absorption spectrum of the iron complex [Fe(phen)3]2+ looks like?

How many electronic spectral bands for Ni^2+ and Co^2+ , one could be expected. Assign these electronic d-d transition bands.

A solution in part C initially contains (4.06x10^-4) molar SCN¯ and (2.960x10^-3) molar Fe3+. This solution was then measured using the colorimeter, and an absorbance of (4.9800x10^-1) was recorded.The constant determined in part A of the experiment was found to be (3.8200x10^3). Using the data provided above, determine the equilibrium concentration of SCN", [SCN]E in this solution. Note: Your answer is assumed to be reduced to the highest power possible. Your Answer: x10 Answer units

A solution of copper(II) sulfate is observed to be blue in color. The maximum absorbance is expected to occur in what wavelength range? 500-560 nm (green) 380-435 nm (violet) 610-750 nm (red) 580-595 nm (yellow) 435-480 nm (blue)

Write the structural formula for 2 isomers of C4H8O2 Additionally, identify two major, and unique, bands in the IR spectrum to identify these compounds. containing different functional groups that would allow you Structural Formula Functional group name Two IR bands

The absorbance of known concentration of a metal complex is obtained by UV-vis spectrophotometer. The results are tabulated: abs 0.27 0.41 0.55 0.69 Calculate the concentration of an unknown sample of the complex that has an absorbance of 0.43 conc 0.2 0.3 0.4 0.5 a. 0.31 b. 0.37 c. 0.33 d. 0.35 e. 0.39 what is the HOMO-LUMO energy gap (AE)? AE-HOMOI-ILUMO a. 10.845 b. 10.877 11.365 d. 11.325 e. 10,383 eV

The absorbance of known concentration of a metal complex is obtained by UV-vis spectrophotometer. The results are tabulated: conc 0.2 0.3 04 0.5 Calculate the concentration of an unknown sample of the complex that has an absorbance of 0.43 0.31 b. 0.37 abs 0.27 0.41 0.55 0.69 c. 0.33 d. 0.35 e. 0.39

If the reaction between Fe(NO3)3 is endothermic, and the system is cooled, would you expect absorbance to go up or down? Explain.

True or false and why is false 1   There are 2 major classes of keratins: alpha keratins (found in mammals) and beta keratins (found in feathers and scales of birds and reptiles) 2  One estimate of mobility within a crystal is the B-factor that reflects spreading or blurring of electron density   3 In NMR, the longitudinal relaxation time (T1) reflects the rate at which magnetization returns to the longitudinal axis after a pulse

Roberta decided to find out the content of nickel (Ni) in a sample. She dissolved the 0.0882 g sample in about 30 mL of nitric acid, and after adding an excess of 8- hydroxyquinolinol (HQL), she diluted the solution with deionized water to a final volume of 250 mL. This final solution showed an absorbance of 0.694 at 365 nm, the wavelength of maximal absorbance of the Ni (HQL) complex, when measured in a 1.00 cm cuvette. Knowing that the trendline from the calibration curve for the Ni(HQL) complex at 365 nm is y = 1500x + 0.029 and that the atomic mass of nickel is 58.693 g/mol, calculate the percent content of Ni by mass in the sample. What is the % nickel by mass in the sample? (a) 5.31 percent (b) 7.38 percent. (c) 7.70 percent. (d) 7.4 percent. (e) None of these

X and Y form a complex whose fluorescence can be measured. Use the following data to determine the concentration of X in the sample. The concentration of X in the standard is 4.15 x 10-³ M. Vx,sample (ml) Vy(ml) Vs.standard (ml) VH20(ml) Rel. F Solution 1 3.0 3.0 0.0 3.0 13.8 Solution 2 3.0 3.0 2.0 1.0 34.3 a. none of the other answers are correct 4.90 x 10-5 M 10-5 M С. 1.86 x d. 7.47 x 10-6 M 10-4 M е. 6.76 x

explain the mechanism

at 580 nm, which is the wavelength of its maximum absorption the complex Fe(SCN)2+ has a molar absoptivity of 7.00x10^3 L cm-1 mol-1. Determine the absorbance of a 3.50 x10^-5 M solution of the complex at 580 nm in a 1 cm cell Express in 3SF

Calculate the absorbance of 2.65*10-5 M solution of the complex at this wavelength using a 1.5 cm cell

A standard iron solution was prepared by dissolving 0.0140 g of pure iron in acid then transferring to a 50.00 mL volumetric flask with orthophenanthroline as a complexing agent. At a wavelength of 540 nm, the absorbance of the standard was 0.214 in a 1.00 cm cuvette. A 0.128 g sample of an iron ore was crushed and digested in 5 mL of concentrated acid. The digested sample was then transferred to a 10.00 mL volumetric flask and diluted to the mark with water. A 1.00 mL aliquot of the sample was transferred to a 25.00 mL volumetric flask, and diluted to the mark with water. A portion of the diluted sample was then transferred to a 1.00 cm cuvette and measured at a wavelength of 540 nm. The resulting absorbance was 0.216. Determine the % w/w of Fe in the iron ore.

A mixture is prepared by combining 11.34 mL of 2.36 x 103 M Fe(NO3)3 with 10.00 mL of 1.66 x 10-3 M KSCN. The solution turns red due to the formation of FeSCN2+. The absorbance is measured and, using a calibration plot, the [FESCN2*] at equilibrium is found to be 2.20 x 10-4 M. Complete the following ICE table Fe3+ SCN 1t FESCN2+ initial (M) (A) (B) (C)0 change (M) (D) (E) (F) equilibrium (M) (G) (H) (1) What is the value of K?

The molar absorptivity (ε) of the FeSCN2+ complex ion is 4700 M-1 · cm-1 at a wavelength of 450 nm. Using a 1-cm sample tube, you measure the absorbance as (2.0x10-1). What is the concentration of FeSCN2+?