7. You are studying a reaction involving o-nitrophenol and want to keep absorption values between 0.2 and 0.8 at 410 nm. What are the lower and upper concentration limits permitted? Concentration (M) · Concentration (μM) Lower 3 3 Upper 3 3 8. You are provided with an NADH solution which you are told was a 150-fold dilution from a stock solution. You record the absorbance of your solution as 0.611 at 340 nm. What was the stock concentration? Stock concentration (M) 3 Stock concentration (mM) 3

Absorbance at 453 nm 8393939 7 fl. oz./20 ml Beer-Lambert's Law (Spectrophotometry) #1 Fe (aq) + KSCN(s) FESCN "(aq) + K" (aq) 3+ To determine the moles of Fe (aq) in a 100. mL sample of an unknown solution, excess KSCN(s) is added to convert all the Fe (aq) into the dark red species FeSCN"(aq), as represented by the equation above. The absorbance of FESCN"(aq) at different concentrations is shown in the graph below. 2+ 0.50 目0.40 0.30 0.20 01 0. 0. 5 x 10-5 10 x 10-5 Concentration of FESCN2+ (M) If the absorbance of the mixture is 0.20 at 453 nm, haw many moles of Fe (aq) were present in the 100. mL sample? (Assume that any volume change due to adding the KSCN(s) Iis negligible.) 3+, 4x10-4 mol 3 x 104 mol (B) 4x 10-6 mol 3x 10-6 mol

2. ] You make 150.0 mL of a copper(II) sulfate solution but forget to cover it before leaving for the day. The next class, you measure the volume and find that you only have 132.0 mL remaining. You didn’t record the initial concentration, but you measure the absorbance of the remaining solution at 620 nm and find that it is 0.386. You also construct the following calibration curve for CuSO4: Standard solution Abs620 0.50 M 0.424 0.40 M 0.336 0.30 M 0.247 0.20 M 0.159 (refer to image) a. What is the value for k (in Beer’s Law)? Provide a calculation or graph to support your answer. b. What is the concentration of the (remaining) solution? c. What was the concentration of the original solution from the first class? d. If you removed 7.5 mL from the 132.0 mL solution in the process of measuring the absorbance, how much water should you add to obtain the original concentration that you solved for in part (c)?

Q3) A solution of Tryptophan has an absorbance at 280 nm of 0.25 in a 0.5 cm length cuvette. Given the absorbance coefficient of Tryptophan is 6.4 × 103 L Mol-1 cm-1. What is the concentration of solution?

The intensity of red light (680 nm) and sorted by a solution of green dye was found to be 1.99 V and the intensity of light when no dye was present (the blank) was found to be 2.69 V.What is the absorbable of the solution of green dye in three significant figures

Guanosine has a maximum absorbance of 275 nm. ϵ275= 8400M−1cm−1 and the path length is 1 cm. Using a spectrophotometer, you find the that A275=0.70. What is the concentration of guanosine?

5 1 point Calculate the keq for ½ B2 + E = D, given: 3A+B22C+2D; Keq = 1.65 x 10-4 3A=2C+2E, Keq = 5.50 × 103.

아 OH OH Reagants needed , Reagunts

Furosemide (MM: 330.7 g/mol) is a diuretic derived from anthranilic acid, this diuretic is used in the treatment of kidney disease, hypertension, liver cirrhosis, and others. Furosemide in alkaline dissolution has an absorption spectrum with a maximum peak centered at 271 nm. The analysis of a furosemide tablet was performed by dissolving its content in a 0.1 mol L-1 NaOH solution and this dissolution completed for a volume of 100 mL, with 1.0 mL of this dissolution was transferred to 50.0 ml and made up to volume with the same solvent. It is dissolution has an absorbance value of 0.475 to 271 nm, with a 1.0 cuvette cm of optical path. At this wavelength, a series of dissolutions of a Standard substance of this drug has the following absorbance measurements (1.0 cm bucket): a) Demonstrate whether the experimental data are in accordance with Bee's law (b) Determine absorptivity and molar absorptivity (c) Determine the amount of drug in the tablet in mg and in ppm (d) Determine the…

How did you decide on the wavelength at which you will read the absorbance of the diluted solutions? What is the importance of reading the absorbance of diluted solutions at λmax? What will vary if you chose a wavelength 20 nm lower or higher than your chosen wavelength? (Minimum of 8 sentences)