A 1.219-g containing (NH4)2SO4, NH4NO3, and nonreactive substances was diluted to 200 mL in a volumetric flask. A 50.00-mL aliquot was made basic with strong alkali, and the liberated NH3 was distilled into 30.00-mL of o.08421 M HCl. The excess HCl required 10.17 mL of o.o8802 M NaOH. A 25-mL aliquot of the sample was made alkaline after the addition of Devarda’s alloy, and the NO3- was reduced to NH3. The NH3 from both the NH4+ and NO3- was then distilled into 30.00 mL of the standard acid and back titrated with 14.16 mL of base. Calculate the percentage of (NH4)2SO4 and NH4NO3 in the sample.

A 1.219-g containing (NH4)2SO4, NH4NO3, and nonreactive substances was diluted to 200 mL in a volumetric flask. A 50.00-mL aliquot was made basic with strong alkali, and the liberated NH3 was distilled into 30.00-mL of o.08421 M HCl. The excess HCl required 10.17 mL of o.o8802 M NaOH. A 25-mL aliquot of the sample was made alkaline after the addition of Devarda’s alloy, and the NO3- was reduced to NH3. The NH3 from both the NH4+ and NO3- was then distilled into 30.00 mL of the standard acid and back titrated with 14.16 mL of base. Calculate the percentage of (NH4)2SO4 and NH4NO3 in the sample.

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter16: Applications Of Neutralization Titrations

Section: Chapter Questions

Problem 16.20QAP

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A 4.912-g sample of a petroleum product was burnedin a tube furnace, and the SO2produced was collectedin 3% H2O2.Reaction:SO2(g)+H2O2→H2SO4A 25.00-mL portion of 0.00873 M NaOH was introducedinto the solution of H2SO4, following whichthe excess base was back-titrated with 15.17 mL of0.01102 M HCl. Calculate the sulfur concentrationin the sample in parts per million.
2.413 g sample contains Na2CO3, NaHCO3 and inert material. This sample was solved in water and diluted to 250.0 ml. 80 ml solution was taken and titrated with 0.09644 N HCl with the indicator of phenolftalein. 6.13 ml HCl was consumed. From a second solution, again 80 ml was taken and titrated with the same HCl solution with the indicator of methylorange. 15.4 ml HCl was consumed. Calculate the percentage of NaHCO3 and Na CO in sample (Na CO =106.0 g/mol, NaHCO =84.02 g/mol)
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A 2.345 g sample of an oat cereal is determined by a Kjeldahl analysis. The sample is digested with H₂SO4, the resulting solution made basic with 45% NaOH, and the NH3 distilled into 50.00 mL of 0.1150 M HCI. The excess HCI is back titrated using 29.30 mL of 0.140 M NaOH using mixed indicator (bromocresol green and methyl red). 1. If the protein in grains averages 15.50% w/w N, what is the % w/w protein in the sample? 2. Why is a mixed indicator used in nitrogen analysis? (Answer in 200 words or less.)
2.4414 g sample containing KCl, K2SO4 and inert materials was dissolved in sufficient water to give 250 mL of solution. A Mohr titration of a 50 mL aliquot required 41.36 mL of 0.05818 M AgNO3. A second 50mL aliquot was treated with 40 mL of 0.1083M NaB(C6H5)4. The reaction is NaB(C6H5)4+ K+ KB(C6H5)4(s) + Na+. The solid was filtered, redissolved in acetone, and titrated with 49.98mL of the AgNO3 solution according to the reaction KB(C6H5)4 + Ag+ AgB(C6H5)4(s) + K+. Calculate the percentage of KCl and K2SO4 in the sample.
2.4414 g sample containing KCl, K2SO4and inert materials was dissolved in sufficient water to give 250 mL of solution. A Mohr titration of a 50 mLaliquot required 41.36 mL of 0.05818 M AgNO3. A second 50mL aliquot was treated with 40 mL of 0.1083M NaB(C6H5)4. The reaction is NaB(C6H5)4+ K=KB(C6H5)4(s)+ Na+. The solid was filtered, redissolved in acetone, and titrated with 49.98mLof the AgNO3solution according to the reaction KB(C6H5)4+ Ag= AgB(C6H5)4(s)+ K+. Calculate the percentage of KCl and K2SO4 in the sample.
2.4414 g sample containing KCl, K2SO4and inert materials was dissolved in sufficient water to give 250 mL of solution. A Mohr titration of a 50 mLaliquot required 41.36 mL of 0.05818 M AgNO3. A second 50mL aliquot was treated with 40 mL of 0.1083M NaB(C6H5)4. The reaction is NaB(C6H5)4+ K+ KB(C6H5)4(s)+ Na+. The solid was filtered, redissolved in acetone, and titrated with 49.98mLof the AgNO3solution according to the reaction KB(C6H5)4+ Ag+ AgB(C6H5)4(s)+ K+. Calculate the percentage of KCl and K2SO4in the sample.
The Merck Index indicates that 10 mg of guanidine,CH5N3, may be administered for each kilogram of bodymass in the treatment of myasthenia gravis. The nitrogenin a 4-tablet sample that had a total mass of 7.50 g wasconverted to ammonia by a Kjeldahl digestion, followedby distillation into 100.0 mL of 0.1750 M HCl. Theanalysis was completed by titrating the excess acid with11.37 mL of 0.1080 M NaOH. How many of thesetablets represent a proper dose for a patient who weighs(a) 100 lb, (b) 150 lb, and (c) 275 lb?
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