ethyl mercaptan concentration in a mixture was determined by shaking a 2.0430-g sample with 50.00 mL of 0.01204 M I2 in a tightly stoppered flask: 2C2H5SH + I2 ---> C2H5SSC2H5 + 2I- + 2H+ The excess I2 was back-titrated with 18.23 mL of 0.01437 M Na2S2O3. Calculate the percentage of C2H5SH (MW = 62.13 g/mol). Millimoles of excess standard I2 solution is ___ 0.5239

ethyl mercaptan concentration in a mixture was determined by shaking a 2.0430-g sample with 50.00 mL of 0.01204 M I2 in a tightly stoppered flask: 2C2H5SH + I2 ---> C2H5SSC2H5 + 2I- + 2H+ The excess I2 was back-titrated with 18.23 mL of 0.01437 M Na2S2O3. Calculate the percentage of C2H5SH (MW = 62.13 g/mol). Millimoles of excess standard I2 solution is ___ 0.5239

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter16: Applications Of Neutralization Titrations

Section: Chapter Questions

Problem 16.40QAP

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A 10.00mL sample of alcoholic ethyl acetate was diluted to 100.00 mL. 20.00 mL was aliquoted and mixed with 40.00 mL of 0.04672 M KOH. The resulting mixture was heated for 2 hours. CH3COOC2H5 + OH- → CH3COO- + C2H5OH After cooling, the excess OH was back titrated with 3.41 mL of 0.05042 M H2SO4. Answer the following: Calculate the number of moles of OH- that reacted with ethyl acetate. Calculate the number of moles of ethyl acetate in the 20.00 mL solution. What is the mass of ethyl acetate (FW=88.11 g/mol) in the original 10.00 mL sample?
A 0.2028 g sample of primary standard grade Na2C2O4 (M.M. = 134.00) was dissolved in 100 mL of 1 M H2SO4. The solution required 22.42 mL of the KMnO4 solution to reach the phenolphthalein end point. Titration of the blank (100 mL of 1M H2SO4) required 0.02 mL of the KMnO4 solution. What is the molarity of KMnO4
H.W 1) Calculate the number of meq. of H;C:O..2H;0 (fw= 126.1) in 0.5 gm of the pure compound assuming that two hydrogen ions to titrated with standard base? 2) A standard AGNO, solution prepared by weighting exactly 24.15 gm of carefully prepared solid, dissolving in water and diluting in a volumetric flask to exactly 2 L. What normality of the solution?
A 0.1093-g sample of impure Na2CO3 was analyzed by the Volhard method. After adding 50.00 mL of 0.06911 M AgNO3, the sample was back-titrated with 0.05781 M KSCN, requiring 27.36 mL to reach the endpoint. Report the purity of the Na2CO3 sample. [Ans. 90.9 % (w /w )]
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The ethyl acetate concentration in an alcoholic solution was determined by diluting a 10.00-mL sample to 100.00 mL. A 20.00-mL portion of the diluted solution was refluxed with 40.00 mL of 0.04672 M KOH:CH3COOC2H5 + OH- → CH3COO- + C2H5OHAfter cooling, the excess OH2 was back-titrated with 3.41 mL of 0.05042 M H2SO4. Calculate theamount of ethyl acetate (88.11 g/mol) in the original sample in grams
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H.W 1) Calculate the number of meq. of H2C204.2H2O (fw= 126.1) in 0.5 gm of the pure compound assuming that two hydrogen ions to titrated with standard base?
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