The Electromotive Force of the Mercurous Bromide Electrode

Crowell, William R.; Mertes, Richard W.; Burke, Simpson S.

doi:10.1021/ja01264a084

Cited by 4 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the course of continuing our previous electrochemical studies in nitrate melts (9)(10)(11), we have now shown that reaction [2] is the correct one in potassium nitrate at 350~ This stoichiometry is maintained for reaction times varying from 1 to 12 hr.…”

Section: Department Of Chemistry University Of Miami Coral Gables mentioning

confidence: 58%

“…The olefin electrode had a potential of 0.45-47V relative to the standard hydrogen electrode based on a mercurymercurous bromide standard potential of 0.139V (11,12).…”

Section: Resultsmentioning

confidence: 99%

“…Under conditions where bromine could be transported as a comp;-ex with bromide ion (in the absence of a diaphragm), product analyses indicated that such transport resulted in formation of dibromoethane. Potentials of individual electrodes were measured on an operating ethylene-bromine cell with LAA-1 electrodes by referring the anode to a mercurous bromide (11,12) electrode with a Luggin capillary. Other experimental details are given in our earlier description of electrogenerative chlorination (3).…”

Section: Methodsmentioning

confidence: 99%

“…Potentials of individual electrodes were measured on an operating ethylene-bromine cell with LAA-1 electrodes by referring the anode to a mercurous bromide (11,12) electrode with a Luggin capillary. Other experimental details are given in our earlier description of electrogenerative chlorination (3).…”

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Electrogenerative Bromination

Miller

Langer

1973

J. Electrochem. Soc.

View full text Add to dashboard Cite

As part of a program to identify and develop techniques for operating feasible electrogenerative processes (1-3), we describe here electrogenerative bromination in which bromine and an olefin are reacted with the aid of suitable electrodes and electrolyte to give dibromoethane and bromohydrin. (We define "electrogenerative processes" as those in which two or more materials react at electrodes so that favorable thermodynamic factors drive the reaction to give a useful chemical product with the generation of byproduct electricity.) Bromine is reduced at the cathode to bromide ions which are transported through the electrolyte to the anode where they combine with olefin, while electrons are conducted through an external circuit to the cathode. Bromine vapor in a nitrogen gas stream and the olefin are introduced to cathode and anode chambers, respectively. The chambers are bounded by gas-permeable, liquid-impermeable electrodes separated by a free electrolyte phase. In contrast to earlier work on other electrogenerative systems (1-3), a diaphragm was needed to separate catholyte and anolyte. This limited the transport of free bromine, probably as Br3-and Brs-(4-6), which would give some direct chemical halogenation of olefin at the anode. Both electrodes operate at positive potentials relative to the standard hydrogen electrode. The rate of bromination and the potential of the cell are controlled by the electrical resistance of the external circuit.Electrode reactions, based on product analyses, with bromide electrolyte appear to be Cathode Br2 -b 2e---# 2Br-[1] Anode RCH=CHR' -{-2Br---> RCH--CHR' -{-2e-[2] L I Br Br or RCH=CHR' -t-2Br-~ H20 --> RCH--CHR' -{-HBr -{-2e-[3] I I Br OHNo significant amount of glycol is formed in the electrolyte. Electrogenerative bromination requires no external power source. Furthermore, we have also used chlorine gas instead of bromine vapor at the cathode where reaction isBr2r "4-2e-~ 2Br-Chlorine gas sometimes can be used advantageously at the cathode because of ease of handling and convenience. ExperimentalA free electrolyte cell similar to that of Landi et al. (7) was used for all runs. It typically can be represented as Olefin I Br-(aq.) ] Membrane ] Br-(aq.) I Br~ Anode Cathode * Electrochemical Society Active Member.where the total free electrolyte chamber thickness varied from 0.25-0.5 in. The cell was constructed so that only the anode, Kel-F, and Teflon came in contact with the olefin. The free electrolyte chamber could be subdivided with diaphragms into two or three compartments. Kel-F inserts were used in the electrolyte chamber to thicken it and were sometimes fitted with inlet and outlet ports to permit electrolyte flow during operation.The electrodes used were gas-permeable, liquidimpermeable commercial American Cyanamid Type LAA-1 (7). They have a platinum black loading of 9 mg/cm 2 on a 50 mesh tantalum screen and are wet proofed with Teflon. In later experiments, carbontetrafluoroethylene film electrodes (8), American Cyanamid LSE, were used on the halogen side of the...

show abstract

Section: Department Of Chemistry University Of Miami Coral Gables mentioning

confidence: 58%

“…The olefin electrode had a potential of 0.45-47V relative to the standard hydrogen electrode based on a mercurymercurous bromide standard potential of 0.139V (11,12).…”

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Electrogenerative Bromination

Miller

Langer

1973

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…The present paper is concerned with a study of hydrogen-mercurous bromide cell, which had not hitherto been adequately investigated. The mercury-mercurous bromide electrode has, however, received much attention [1][2][3][4][5][6][7][8] and both of the cells have been studied over narrow ranges of electrolyte concentrations and temperatures. The standard electrode potential of the mercury-mercurous bromide electrode has not, however, been determined directly, but only by use of existing values of mean molal ionic activity coefficients of hydrobromic acid in aqueous solution (cell A), or of the standard potential of the silver-silver bromide electrode (cell B).…”

mentioning

confidence: 99%

Standard E.m.f. of the hydrogen-mercurous bromide cell from 5 to 45°C

Gupta¹,

Hills²,

Ives³

1963

Trans. Faraday Soc.

View full text Add to dashboard Cite

The cell H2, Pt I HBr(aq) 1 Hg2Br2 I Hg has been found to behave similarly to the hydrogencalomel cell, but increased difficulties are encountered because of the more ready disproportionation of the mercurous halide. E.m.f. of the cell have been measured at 5 deg. intervals between 5 and 45°C for hydrobromic acid solutions between 0.005 and 0-2 molal, and have been used to obtain the first direct determinations of standard e.m.f.s. Thermodynamic functions of the cell reaction have been evaluated as have activity coefficients of aqueous HJ3r.

show abstract

Literature References

1971

Selected Constants

View full text Add to dashboard Cite

The Electromotive Force of the Mercurous Bromide Electrode

Cited by 4 publications

References 0 publications

Electrogenerative Bromination

Electrogenerative Bromination

Standard E.m.f. of the hydrogen-mercurous bromide cell from 5 to 45°C

Literature References

Contact Info

Product

Resources

About