The Thermodynamic Ionization Constants of Sulfurous Acid at 25°1

Abstract Corrosion rate data are presented for low carbon steel in (1) a combination of sulfur dioxide, water vapor and air, and (2) aqueous solutions of sulfurous acid in the absence of air, at ordinary temperature. Information as to the nature of the corrosion products is presented and it is shown that this depends on the place in which the corrosion takes place to an important extent.

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THE IONIZATION CONSTANTS OF p-NITROPHENYLACETIC AND PHENYLMALONIC ACIDS

Canadian Journal of Research ◽

10.1139/cjr33-044 ◽

1933 ◽

Vol 8 (5) ◽

pp. 447-449 ◽

Cited By ~ 5

Author(s):

Steward Basterfield ◽

James W. Tomecko

Keyword(s):

Benzoic Acid ◽

Nitro Group ◽

Malonic Acid ◽

Phenylacetic Acid ◽

Ionization Constants ◽

Side Chain ◽

Cooh Group ◽

Conductivity Data ◽

Nitrobenzoic Acid ◽

Phenylmalonic Acid

The ionization constants of p-nitrophenylacetic and phenylmalonic acids have been determined from conductivity data. The value of K for p-nitrophenylacetic acid at 25 °C. is 1.04 × 10−4, about twice that of phenylacetic acid. The nitro group in the nucleus has not as powerful an effect on the ionization when the COOH group is in the side chain as it has when both nitro group and COOH are in the nucleus. K for p-nitrobenzoic acid is six times as great as K for benzoic acid. K for phenylmalonic acid is 2. 77 × 10−3 as compared with 1.6 × 10−3 for malonic acid.

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Mathematical Modeling of Betanin Extraction from Red Beet (Beta vulgaris L.) by Solid–Liquid Method

International Journal of Food Engineering ◽

10.1515/ijfe-2014-0098 ◽

2015 ◽

Vol 11 (1) ◽

pp. 17-22 ◽

Cited By ~ 2

Author(s):

Honggao Xu ◽

Qiang Peng ◽

Fang Yuan ◽

Yanxiang Gao

Keyword(s):

Mathematical Modeling ◽

Effective Diffusion ◽

Spherical Model ◽

Extraction Process ◽

Extraction Temperature ◽

Optimal Parameters ◽

Practical Application ◽

Sulfurous Acid ◽

Red Beet ◽

Solid Liquid

Abstract Effective diffusion coefficient (D-value) is an important parameter for the extraction process. In this study, a cylindrical model to estimate the D-value of betanin extraction from red beet roots was developed. The influence of extraction temperature, pH, cylindrical thickness and type of acids on the D-value was also investigated. The optimal parameters of betanin extraction were 30°C, pH 4.0 adjusted with sulfurous acid or acetic acid. D-values under the above conditions were 18.95×10−11 m2/s and 17.87×10−11 m2/s, respectively. The result showed that D-value elevated with the increase of cylindrical thickness, which was consistent with earlier conclusion from spherical model. The modeling may be useful for the investigation into extraction process and practical application.

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