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12 Nov 2019
1. The following question is about Beer's Law. What is Beer's Law? P.113 a. b. What is meant by deviations from Beer's Law? c. What are the three assumptions underlying Beer's Law? 3 in a lem cell. Calculate the molar absorptivity at 266nm. Ar & bc length and concentration were cut in half? ã« 2. The absorbance of a 2.31x10 M solution of a compound is 0.822 at a wavelength of 266nm 3ã The absorbance of a solution is 0.740, what would be the absorbance if both the path ã4. A 3.96x10-M solution of compound A exhibited an absorbance of 0.624 at 238nm in a Iem cell. A solution containing only solvent (i.e., blank) had an absorbance value of 0.02 at the same wavelength. Find the molar absorptivity of compound A. 5. Using the following table of prominent absorption wavelengths and molar absorptivities for naphthalene and anthracene, suggest a wavelength at which anthracene can be determined in the presence of an unknown amount of naphthalene and calculate the minimum detectable concentration of anthracene at the optimum wavelength. Assume a cell path length of 100 cm and the minimum detectable concentration corresponds to an absorbance of 0.0132. Absorption Wavelength Molar Absorptivity 221 286 312 375 221 312 375 Compound Naphthalene 9300 290 Anthracene 15,000 1200 9000 A compound with a molecular weight of 292.16 was dissolved in a 5ml volumetric flask. A Iml aliquot was withdrawn, placed in a 10ml volumetric flask and diluted to the mark. The absorbance at 340nma was 0.427 in a 1 cm cuvette ε for this compound at 340nn is 6130M'cm 6. Calculate the concentration of the compound in the cuvette What is the concentration of the compound in the 5ml flask a. b. c. How many milligrams of compound were used to make the 5ml solution? An acid, HTS, is added to 1M acetic acid/acetate buffer (pH 4) to yield a 0.001M solution. HTS does not absorb whereas TS does absorb in the visible region (A-540c for 1- 650nm with c is in molarity.) If the absorbance signal from the 10 3M solution is 0.27, what is K of HTS? For an 8x10- M methyl red solution at pH 5, As25am is 0.92. (1cm cells were used to make this measurement.) The experimenters ascertained the following two facts about 7.
1. The following question is about Beer's Law. What is Beer's Law? P.113 a. b. What is meant by deviations from Beer's Law? c. What are the three assumptions underlying Beer's Law? 3 in a lem cell. Calculate the molar absorptivity at 266nm. Ar & bc length and concentration were cut in half? ã« 2. The absorbance of a 2.31x10 M solution of a compound is 0.822 at a wavelength of 266nm 3ã The absorbance of a solution is 0.740, what would be the absorbance if both the path ã4. A 3.96x10-M solution of compound A exhibited an absorbance of 0.624 at 238nm in a Iem cell. A solution containing only solvent (i.e., blank) had an absorbance value of 0.02 at the same wavelength. Find the molar absorptivity of compound A. 5. Using the following table of prominent absorption wavelengths and molar absorptivities for naphthalene and anthracene, suggest a wavelength at which anthracene can be determined in the presence of an unknown amount of naphthalene and calculate the minimum detectable concentration of anthracene at the optimum wavelength. Assume a cell path length of 100 cm and the minimum detectable concentration corresponds to an absorbance of 0.0132. Absorption Wavelength Molar Absorptivity 221 286 312 375 221 312 375 Compound Naphthalene 9300 290 Anthracene 15,000 1200 9000 A compound with a molecular weight of 292.16 was dissolved in a 5ml volumetric flask. A Iml aliquot was withdrawn, placed in a 10ml volumetric flask and diluted to the mark. The absorbance at 340nma was 0.427 in a 1 cm cuvette ε for this compound at 340nn is 6130M'cm 6. Calculate the concentration of the compound in the cuvette What is the concentration of the compound in the 5ml flask a. b. c. How many milligrams of compound were used to make the 5ml solution? An acid, HTS, is added to 1M acetic acid/acetate buffer (pH 4) to yield a 0.001M solution. HTS does not absorb whereas TS does absorb in the visible region (A-540c for 1- 650nm with c is in molarity.) If the absorbance signal from the 10 3M solution is 0.27, what is K of HTS? For an 8x10- M methyl red solution at pH 5, As25am is 0.92. (1cm cells were used to make this measurement.) The experimenters ascertained the following two facts about 7.
Keith LeannonLv2
7 Nov 2019