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Polarography of 4‐Nitrophthalic Acid
Author(s) -
Sharma S. K.
Publication year - 1975
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.197500030
Subject(s) - chemistry , polarography , nitro , ionic bonding , diffusion , dropping mercury electrode , adsorption , kinetic energy , electrode , electrochemistry , analytical chemistry (journal) , inorganic chemistry , stereochemistry , ion , thermodynamics , organic chemistry , alkyl , physics , quantum mechanics
The–NO 2 group reduction in 4‐nitrophthalic acid (NPA) at dropping mercury electrode over a wide range of P H, is irreversible and diffusion controlled. Ill defined waves preceded the —NO 2 group wave, were observed between P H 7 and 12 whereas at P H 5.0, a rounded maximum appears. The a. c. reduction of NPA at P H 12.0, provides two peaks, first peak corresponds to d. c. pre‐step, is essentially due to adsorption phenomena whereas other peak is the reduction wave. Using McBain Down cell and King‐cathcart equation the diffusion coefficient of NPA is 0.713×10 ‐3 cm 2 sec ‐1 . Six electrons are being involved in nitro group reduction and mechanism of the reduction was suggested. The kinetic parameters in absence and presence of ionic and non‐ionic surfactants were determined. The reduction process becomes more and more irreversible as surface activity of organic compounds increases. Ionic surfactants are effective in increasing the value of —log K° than the non‐ionic surfactants. The value of ana decreases regularly by the presence of compounds having regular increase of surface activity.