Sodium sulfite

About: Sodium sulfite is a research topic. Over the lifetime, 2548 publications have been published within this topic receiving 18523 citations. The topic is also known as: Na2SO3 & Anhydrous sodium sulfite.

Photolysis of p-benzoquinone and p-chloranil in aqueous sodium sulfite solution

Abstract: Photosubstitution of the sulfo group for hydrogen (chlorine in chloranil) is observed under irradiation of sulfonated derivatives of hydroquinone formed upon dissolving of p-benzoquinone and p-chloranil in aqueous solutions of sodium sulfite. The quantum yield of the photochemical reaction is 0.18 ± 0.02 for p-benzoquinone. The rate constant of the thermal reaction of substitution is 5.5 × 10−4 l mol−1 s−1. The substitution reaction is sensitized by eosin upon irradiation with visible light. During the course of irradiation of sulfohydroquinones, the formation of a product with an absorption maximum at 235 nm was found. The product decays with a rate constant of 0.005 s−1.

Cleavage of disulfide polymers. I. By inorganic sulfides

Abstract: Although sodium disulfide is one of the chief reactants in the preparation of polymeric disulfides, it has the ability to cleave the disulfide links in the polymer, as is shown in this paper. This cleavage is responsible for losses in yield of polymer through solubilization of fragments of low molecular weight, but is it also necessary in producing high polymers. The unreactive terminal hydroxyl groups produced by the side reaction of alkaline hydrolysis of reactive chloride terminals would ordinarily limit the chain length of the polymer; however, the preferential solubilization of the terminal fragments, because of the hydrophilic hydroxy group, permits the molecular weight of the polymer to be increased greatly. An excess of sodium disulfide is thus needed in order to obtain disulfide polymers of high molecular weight, in contrast to the usual condensation polymerization wherein an exact equivalence of reactants is needed. The cleavage of the aliphatic disulfide groups in the polymer by aqueous sodium polysulfide is a reversible reaction with the equilibrium favoring re-formation of the disulfide linkage. The equilibrium is displaced if a reagent capable of binding sulfur is present. A mixture of sodium sulfide, in particular sodium hydrosulfide, with sodium sulfite can be used in an efficient and controllable manner to convert polymer disulfides of high molecular weight to polymers of low molecular weight with terminal thiol groups.

Operating method of absorption type freezer and absorption liquid for absorption type freezer

Abstract: PURPOSE: To restrict occurrence of hydrogen gas caused by a local corrosion or an entire surface corrosion and to enable an operation of a freezer to be carried out in the case that an equipment made of stainless steel acting as composing equipment in an absorption type freezer with lithium bromide solution being applied as absorption liquid. CONSTITUTION: In an operation of an absorption type freezer having lithium bromide (LiBr) aqueous solution applied as absorption liquid and having an equipment made of stainless steel, the operation is carried out while applying absorption liquid for the absorption type freezer with a concentration of lithium hydroxide (LiOH) being 0.01. to 0.3N, with sodium sulfite (Na2 SO3 ) or sodium hydrogen sulfite (NaHSO3 ) of 250ppm or more in a conversion rate of sodium sulfite and further antimony chloride (SbCl3 ) or antimony oxide (Sb2 O3 ) of 200 to 2000ppm or more in a conversion rate of antimony chloride.

Determination of aminophenols and phenol in hair colorants by ultrasound‐assisted solid‐phase dispersion extraction coupled with ion chromatography

Abstract: A simple and reliable ultrasound-assisted solid-phase dispersion extraction coupled with ion chromatography was developed for the determination of aminophenols and phenol. The highly viscous hair colorant was dispersed in solvents using anhydrous sodium sulfite having dual functions of dispersant and antioxidant. The use of anhydrous sodium sulfite did not change the sample volume because it could completely dissolve in solution after matrix dispersion. The extraction and cleanup were combined in one single step for simplifying operation. The extraction process could be rapidly accomplished within 9 min with high sample throughput under the synergistic effects of vibration, ultrasound, and heating. Satisfactory linearity was observed with correlation coefficients higher than 0.9992, and the limits of detection varied from 0.02 to 0.09 mg/L. The applicability of the proposed method was demonstrated by measuring the concentrations of aminophenols and phenol in 32 different commercial hair color products. The recoveries ranged from 86.4-101.2% with the relative standard deviations in the range of 0.52-4.3%. The method offers an attractive alternative for the analysis of trace phenols in complex matrices.