Principles of Instrumental Analysis
7th Edition
ISBN: 9781305577213
Author: Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Question
Chapter 24, Problem 24.8QAP
Interpretation Introduction
Interpretation:
The percent CCl4 and CHCl3 in each mixture should be calculated.
Concept introduction:
Coulometry is a quantitative analytical technique which involve measuring the quantity of electricity required to convert the analyte to a different oxidation state.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
At a potential of –1.0 V (versus SCE), carbon tetrachloride in methanol is reduced to chloroform at a Hg
cathode:
2CCI, + 2H*+ 2e¯+ 2Hg(1)
→ 2CHCI, + Hg,Cl,(s)
At -1.80 V, the chloroform further reacts to give methane:
2CHCI, + 6H+ + 6e¯+ 6Hg(1)
→ 2CH, + 3Hg,Cl,(s)
Several 0.750-g samples containing CCL4, CHCI,, 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 CCl, and CHCI, in each mixture.
Charge Required
at –1.0 V, C
Charge Required
at –1.8 V, C
Sample No.
1
10.84
69.20
2
20.52
88.50
3
6.22
45.98
4
11.60
68.62
(a) Determine the mass of Na,S2O3.5H20 required to prepare 0.1N solution
in 50 ml volume.
(b) Compare combustion of Anthracene and Xylene in sufficient supply of
air. Which one will produce more carbon rich sooty flame and why?
(c) Consider electrode potential data given in Question 4 (c). Predict which
two electrodes combination will give maximum potential. Provide
justification.
(d) Explain two industrial applications of acidic buffer solutions.
(e) Discuss the importance of Hess law with suitable example.
The standard reduction potential (Eo) for the conversion of Cr2O72- to Cr3+ at 25 degree C in an aqueous solution of pH 3.0 is 1.33 V. The concentrations of Cr2O72- and Cr3+ are1.0 × 10-4 M and 1.0 × 10-3 M, respectively. Then the potential of this half-cell reaction is (Given: Faraday constant = 96500 C mol1, Gas constant R = 8.314 J K1 mol1)
Chapter 24 Solutions
Principles of Instrumental Analysis
Ch. 24 - Prob. 24.1QAPCh. 24 - Calculate the minimum difference in standard...Ch. 24 - Prob. 24.3QAPCh. 24 - Halide ions can he deposited at a silver anode,...Ch. 24 - What cathode potential (versus SCE) would be...Ch. 24 - Calculate the Lime required for a constant current...Ch. 24 - Calculate the time required for a constant current...Ch. 24 - Prob. 24.8QAPCh. 24 - Prob. 24.9QAPCh. 24 - A 0.0712-g sample of a purified organic acid was...
Knowledge Booster
Similar questions
- Halide ions can he deposited at a silver anode, the reaction being Ag(s) + X- AgX(s) +e- Suppose that a cell was formed by immersing a silver anode in an analyte solution that was 0.0250 M Cl-,Br-, and I -ions and connecting the half-cell to a saturated calomel cathode via a salt bridge. (a) Which halide would form first and at what potential? Is the cell galvanic or electrolytic? (b) Could I- and Br- be separated quantitatively? (Take 1.00 l0-5 M as the criterion for quantitative removal of an ion.) If a separation is feasible, what range of cell potential could he used? (c) Repeat part (b) for I- and Cl-. (d) Repeat part (b) for Br- and Cl-.arrow_forwardGalvanic cells harness spontaneous oxidationreduction reactions to produce work by producing a current. They do so by controlling the flow of electrons from the species oxidized to the species reduced. How is a galvanic cell designed? What is in the cathode compartment? The anode compartment? What purpose do electrodes serve? Which way do electrons always flow in the wire connecting the two electrodes in a galvanic cell? Why is it necessary to use a salt bridge or a porous disk in a galvanic cell? Which way do cations flow in the salt bridge? Which way do the anions flow? What is a cell potential and what is a volt?arrow_forwardThe following cell was found to have a potential of —0.492 V: Ag|AgCl(sat’d)||HA(0.200 M),NaA(0.300 M)|H2(1.00 atm),Pt Calculate the dissociation constant of HA, neglecting the junction potential.arrow_forward
- For the following half-reaction, = 2.07 V: A1F63(aq)+3eAl(s)+6F(aq) Using data from Table 17-1, calculate the equilibrium constant at 25C for the reaction A13+(aq)+6F(aq)A1F63(aq)K=?arrow_forwardThe table below lists the cell potentials for the 10 possible galvanic cells assembled from the metals A. B. C. D. and E. and their respective 1.00 M 2+ ions in solution. Using the data in the table, establish a standard reduction potential table similar to Table 17-1 in the text. Assign a reduction potential of 0.00 V to the half-reaction that falls in the middle of the series. You should get two different tables. Explain why, and discuss what you could do to determine which table is correct. A(s)in A2+(aq) B(s)in B2+(aq) C(s)in V2+(aq) D(s)in D2+(aq) E(s)in E2+(aq) 0.28V 0.81V 0.13V 1.00V D(s)in D2+(aq) 0.72V 0.19V 1.13V C(s)in V2+(aq) 0.41V 0.94V B(s)in B2+(aq) 0.53Varrow_forwardAn aqueous solution of an unknown salt of vanadium is electrolyzed by a current of 2.50 amps for 1.90 hours. The electroplating is carried out with an efficiency of 95.0%, resulting in a deposit of 2.850 g of vanadium. a How many faradays are required to deposit the vanadium? b What is the charge on the vanadium ions (based on your calculations)?arrow_forward
- A galvanic cell is based on the following half-reactions: In this cell, the copper compartment contains a copper electrode and [Cu2+] = 1.00 M, and the vanadium compartment contains a vanadium electrode and V2+ at an unknown concentration. The compartment containing the vanadium (1.00 L of solution) was titrated with 0.0800 M H2EDTA2, resulting in the reaction H2EDTA2(aq)+V2+(aq)VEDTA2(aq)+2H+(aq)K=? The potential of the cell was monitored to determine the stoichiometric point for the process, which occurred at a volume of 500.0 mL H2EDTA2 solution added. At the stoichiometric point, was observed to be 1 .98 V. The solution was buffered at a pH of 10.00. a. Calculate before the titration was carried out. b. Calculate the value of the equilibrium constant, K, for the titration reaction. c. Calculate at the halfway point in the titration.arrow_forwardWhat is the cell potential of the following cell at 25C? Ni(s)Ni2+(1.0M)Sn2(1.5104M)Sn(s)arrow_forwardThe cell potential of the following cell at 25C is 0.480 V. ZnZn2+(1M)H+(testsolution)H2(1atm)Pt What is the pH of the test solution?arrow_forward
- What cathode potential (versus SCE) would be required to lower the total Hg(II) concentration of the following solutions to 1.00 10-6 M (assume reaction product in each case is elemental Hg): (a) an aqueous solution of Hg2+? (b) a solution with an equilibrium SCN- concentration of 0.100 M? Hg2+ + 2SCN- Hg(SCN)2(aq) = Kf = 1.8 107 c) a solution with an equilibrium Br- concentration of 0.100 M? HgBr42++ 2e- Hg(l) + 4Br- E0= 0.223 Varrow_forwardCalculate the standard cell potential of the following cell at 25C. Cr(s)Cr3(aq)Hg22(aq)Hg(l)arrow_forwardA 0.0712-g sample of a purified organic acid was dissolved in an alcohol-water mixture and titrated with coulometrically generated hydroxide ions. With a current of 0.0392 A, 241 s was required to reach aphenolphthalein end point. Calculate the equivalent mass of the acid.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
General Chemistry - Standalone book (MindTap Cour...ChemistryISBN:9781305580343Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; DarrellPublisher:Cengage Learning
ChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage Learning
Chemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage Learning
Principles of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning
Chemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning
General Chemistry - Standalone book (MindTap Cour...
Chemistry
ISBN:9781305580343
Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; Darrell
Publisher:Cengage Learning
Chemistry
Chemistry
ISBN:9781305957404
Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:Cengage Learning
Chemistry: An Atoms First Approach
Chemistry
ISBN:9781305079243
Author:Steven S. Zumdahl, Susan A. Zumdahl
Publisher:Cengage Learning
Principles of Instrumental Analysis
Chemistry
ISBN:9781305577213
Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:Cengage Learning
Chemistry & Chemical Reactivity
Chemistry
ISBN:9781337399074
Author:John C. Kotz, Paul M. Treichel, John Townsend, David Treichel
Publisher:Cengage Learning