Sulfite ions

The reaction of the hydrogen sulfite ion in an alkaline solution with ketones and aldehydes is ... 

Chloride. Chloride is common in freshwater because almost all chloride salts are very soluble in water. Its concentration is generally lO " to 10 M. Chloride can be titrated with mercuric nitrate. Diphenylcarbazone, which forms a purple complex with the excess mercuric ions at pH 2.3—2.8, is used as the indicator. The pH should be controlled to 0.1 pH unit. Bromide and iodide are the principal interferences, whereas chromate, ferric, and sulfite ions interfere at levels greater than 10 mg/L. Chloride can also be deterrnined by a colorimetric method based on the displacement of thiocyanate ion from mercuric thiocyanate by chloride ion. The Hberated SCN reacts with ferric ion to form the colored complex of ferric thiocyanate. The method is suitable for chloride concentrations from 10 to 10 M. 

The reaction of benzenesulfonic acid with sodium hydroxide (first entry in Table 24.3) proceeds by the addition-elimination mechanism of nucleophilic aromatic substitution (Section 23.6). Hydroxide replaces sulfite ion (S03 ) at the carbon atom that bear s the leaving group. Thus, p-toluenesulfonic acid is converted exclusively to p-cresol by an analogous reaction ... 

Only with large cations such as Rb, Cs and NRafR = Et, Bu", n-pentyl) has it proved possible to isolate the. solid sulfites The sulfite ion SOs is pyramidal with Cj,. symmetry angle O-S-O 106°, S-O 151 pm. The hydrogen sulfite ion also appears to have C3, symmetry both in the solid state and in solution, i.e. protonation occurs at S rather than... 

Sulfonic acids containing nitrogen have long been implicated as essential intermediates in the synthesis of H2SO4 by the lead-chamber process (p. 708) and, as shown by F. Seel and his group, the crucial stage is the oxidation of sulfite ions by the nitrosyl ion NO+ ... 

Figure 10-6 continues this pictorial presentation of solubilities. Figure 10-6A shows the positive ions that form hydroxides of low solubility. Figure 10-6B shows the positive ions that have low solubility when combined with phosphate ion, PO 3, carbonate ion, CO 2, and sulfite ion,... 

In spite of its wide application, the mechanisms of this reaction remain obscure. Many diverse arguments have been published since the reaction was first investigated in 1897 (Bl, C5, C9, F7, J6, M5, P9, R2, S5, W2, W4, Yl, Y4). Cooper et al. (C9) introduced this method as a yardstick for the measurement of volumetric mass-transfer coefficients in gas-liquid contacting. Karow et al. (Kl) later concluded that the sulfite oxidation is suitable for fermentation process scale-up studies. Cooper et al. established that the reaction proceeds at a rate independent of sulfite ion concentration over wide concentration ranges. In their work they considered the sulfite oxidation to be of zero order with respect to both sulfite and sulfate concentration. 

The formation of diazosulfones and diazosulfonates can also be described as S-coupling. Here the sulfur atom of the sulfinic acid or the sulfite ion, respectively, appears as the basic centre of the nucleophilic component, whereas the oxygen atoms do... 

Z)-compounds are formed in reactions with hydroxide, methoxide, cyanide, and sulfite ions, whereas (ii)-compounds are formed in most reactions with amines (formation of triazenes) and with diazo coupling components such as phenols and aromatic tertiary amines. 

L.21 Thiosulfate ions (S,0,2-) disproportionate in acidic solution to give solid sulfur (S) and hydrogen sulfite ion (HSO ) ... 

Write the Lewis structure, including typical contributions to the resonance structure (where appropriate, allow for the possibility of octet expansion, including double bonds in different positions), for (a) sulfite ion (b) hydrogen sulfite ion (c) perchlorate ion (d) nitrite ion. 

F are 0, whereas, in the second structure, Xe is —1, one F is 0, and the other F is +1. The first structure is favored on the basis of formal charges, (b) In the first structure, all of the atoms have formal charges of 0, whereas, in the second structure, one O atom has a formal charge of +1 and the other O has a formal charge of - 1. The first structure is thus preferred, 2.55 (a) The sulfite ion has one Lewis structure that obeys... 

Notice that, unlike the sulfite ion, which has three resonance forms, the presence of the hydrogen ion restricts the electrons to the oxygen atom to which it is attached. Because H is electropositive, its placement near an oxygen atom makes it less likely for that oxygen atom to donate a lone pair to an adjacent atom. 

Sulfite ions react with polysulfide ions at 50 °C in neutral solution to thiosulfate and monosulfide, e.g. ... 

Alkyl halides react with sulfite ion to form alkyl sulfonates, a reaction known as the Strecker reaction (20). "Organic Syntheses"... 

With these results, we named the new enzyme as phenylacetaldoxime dehydratase (EC 4.99.1.7). It was also suggested that the enzyme utilizes FMN as an electron acceptor, because the value was increased about five times under anaerobic condition and the sulfite ion could replace FMN, although the enzyme requires oxidized form of FMN. It was revealed that the enzyme is a quite unique enzyme whose apparent function is to catalyze a dehydration reaction. The reaction mechanism is of much interest. 

The different coordination behaviour of F- and 0-ligands in the [P03F] ion becomes evident in the interesting structural isomery of (NH4)2P03F H2O (26) and (NH4)2S03 H2O (28) also, the stmctural parameters of which are very much alike -the part of the F-atom in the fluorophosphate being played by the lone electron pair in the sulfite ion. 

There are also some polyatomic ions that end with the letters -ite. S032- and N02 are examples of polyatomic ions with -ite endings. The ion S032- is called a sulfite ion and N02 is a nitrite ion. To name an acid that contains a polyatomic ion that ends in -ite, change the -ite to -ous and add the word acid. Therefore, the name for H2SOs is sulfurous acid and HN02 is nitrous acid. 

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