Article pubs.acs.org/jced
Equilibrium Solubility of Sodium 3‑Nitrobenzenesulfonate in Binary NaCl + H2O, Na2SO4 + H2O, and C2H5OH + H2O Solvent Mixtures at Elevated Temperatures from (273.15 to 323.15) K Rong-Rong Li,*,†,‡ Hua-Ding Liang,† Chang-Hua Ge,† Cai-Ping Lin,† Yu-Jing You,† and Bo Zhao† †
School of Pharmaceutical and Chemical Engineering, TaiZhou University, Linhai, Zhejiang, 317000, P. R. China Institute of Industrial Catalysis, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, P. R. China
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ABSTRACT: The solubility of sodium 3-nitrobenzenesulfonate in binary NaCl + H2O, Na2SO4 + H2O, and C2H5OH + H2O solvent mixtures were measured at elevated temperatures from (273.15 to 323.15) K by a steadystate method. The results of these measurement were correlated by a modified Apelblat equation.
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INTRODUCTION Sodium 3-nitrobenzenesulfonate (CAS Registry No. 127-68-4) is a commercially valuable intermediate, which is commonly used in the preparation of pigments, dye solutes, ionic liquids, and high polymers.1−4 It is generally obtained by the sulfonation of nitrobenzene using concentrated H2SO4. The isomeric mixtures of sodium 3-nitrobenzenesulfonate and sodium 4-nitrobenzenesulfonate are formed in proportions of this method. The whole usage needs to purify the product of sodium 3-nitrobenzenesulfonate. It is very hard to separate high-purity sodium 3-nitrobenzenesulfonate from the mixture, which is from this reaction product. The profitable product of sodium 3-nitrobenzenesulfonate is produced via crystallization in NaCl, Na2SO4, or C2H5OH aqueous solution. To purify sodium 3-nitrobenzenesulfonate using a simple method, the solubility of sodium 3-nitrobenzenesulfonate in binary NaCl + H2O, Na2SO4 + H2O, and C2H5OH + H2O solvent mixtures are needed. On the basis of this problem, we recently published a paper on the solubility of sodium 4-nitrobenzenesulfonate in NaCl, Na2SO4, and C2H5OH aqueous solution.5 Although the solubility data of sodium 3-nitrobenzenesulfonate in NaCl, Na2SO4, and C2H5OH aqueous solution is very significant to the crystallization process, up to now, no literature have been reported on the solubility of sodium 3-nitrobenzenesulfonate.6−8 Therefore, the present work is concerned with a systematic determination of the solubility of sodium 3nitrobenzenesulfonate in binary NaCl + H2O, Na2SO4 + H2O, and C2H5OH + H2O solvent mixtures was determined by steady-state method from (273.15 to 323.15) K.9−13 The results of these measurements were correlated by a modified Apelblat equation. © 2012 American Chemical Society
EXPERIMENTAL SECTION Chemicals. Sodium 3-nitrobenzenesulfonate with a mass purity of 0.995 was supplied by YuanCheng Chemical Co. Ltd. (China), which was used without further purification. The mass fraction purity of sodium 3-nitrobenzenesulfonate was analyzed by high-performance liquid chromatography (HPLC) and determined to be no less than 0.995. The melting temperature of sodium 3-nitrobenzenesulfonate is 350.1 °C which was determined by differential scanning calorimetry (DSC). Na2SO4 and NaCl had a mass purity of 0.998 and 0.996, respectively, and were supplied by Shenyang Chemical Reagent Co. C2H5OH was purchased by Shanghai Chemical Reagent Co. had a mass purity of 0.999. The water was twice-distilled water (conductivity
