H2S content can be determined quantitatively via coulometric titration. In this case, I3 was used as titrant while KI serves as mediator. Assume that 50 mL of unknown sample was pipetted into a coulometric cell. Subsequently, excess KI was added and titration began. A small amount of starch powder was added after 5 minutes to visualise the titration end point. Given a constant current of 94.6 mA was applied throughout the entire electrolysis process which took 406 s to finish. Report the concentration of H2S (34.08 g/mol) of unknown sample in parts per million. (F= 96485 C/mol e H2S(ag) + I3 (ag) + 2H2O) 2H3O* (ag) + 3I (aq) + S(s)

H2S content can be determined quantitatively via coulometric titration. In this case, I3 was used as titrant while KI serves as mediator. Assume that 50 mL of unknown sample was pipetted into a coulometric cell. Subsequently, excess KI was added and titration began. A small amount of starch powder was added after 5 minutes to visualise the titration end point. Given a constant current of 94.6 mA was applied throughout the entire electrolysis process which took 406 s to finish. Report the concentration of H2S (34.08 g/mol) of unknown sample in parts per million. (F= 96485 C/mol e H2S(ag) + I3 (ag) + 2H2O) 2H3O* (ag) + 3I (aq) + S(s)

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter8: Sampling, Standardization, And Calibration

Section: Chapter Questions

Problem 8.15QAP

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