At a potential of -1.0 V (versus SCE), carbon tetrachloride in methanol is reduced to chloroform at a Hg cathode: 2CCl4 + 2H+ + 2e + 2Hg (1) ⇒ 2CHCl3 + Hg2 Cl₂ (8) At -1.80 V, the chloroform further reacts to give methane: 2CHCl3 + 8H+ + Be + 6Hg(1)→ 2CH4 + 3Hg2Cl₂ (8) Several 0.850-g samples containing CC14, CHCl3, and inert organic species were dissolved in methanol and electrolyzed at -1.0 V until the current approached zero. A coulometer indicated the charge required to complete the reaction, as given in the second column of the following table. The potential of the cathode was then adjusted to -1.80 V. The additional charge required to complete the reaction at this potential is given in the third column of the table. Calculate the percent CCl4 and CHCI 3 in each mixture.

At a potential of -1.0 V (versus SCE), carbon tetrachloride in methanol is reduced to chloroform at a Hg cathode: 2CCl4 + 2H+ + 2e + 2Hg (1) ⇒ 2CHCl3 + Hg2 Cl₂ (8) At -1.80 V, the chloroform further reacts to give methane: 2CHCl3 + 8H+ + Be + 6Hg(1)→ 2CH4 + 3Hg2Cl₂ (8) Several 0.850-g samples containing CC14, CHCl3, and inert organic species were dissolved in methanol and electrolyzed at -1.0 V until the current approached zero. A coulometer indicated the charge required to complete the reaction, as given in the second column of the following table. The potential of the cathode was then adjusted to -1.80 V. The additional charge required to complete the reaction at this potential is given in the third column of the table. Calculate the percent CCl4 and CHCI 3 in each mixture.

Principles of Instrumental Analysis

7th Edition

ISBN:9781305577213

Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Chapter24: Coulometry

Section: Chapter Questions

Problem 24.8QAP

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