Hydroxide reaction + acids

Methylene iodide [75-11-6], CH2I2, also known as diio dome thane, mol wt 267.87, 94.76% I, mp 6.0°C, and bp 181°C, is a very heavy colorless Hquid. It has a density of 3.325 g/mL at 20°C and a refractive index of 1.7538 at 4°C. It darkens in contact with air, moisture, and light. Its solubiHty in water is 1.42 g/100 g H2O at 20°C it is soluble in alcohol, chloroform, ben2ene, and ether. Methylene iodide is prepared by reaction of sodium arsenite and iodoform with sodium hydroxide reaction of iodine, sodium ethoxide, and hydroiodic acid on iodoform the oxidation of iodoacetic acid with potassium persulfate and by reaction of potassium iodide and methylene chloride (124,125). Diiodoform is used for determining the density and refractive index of minerals. It is also used as a starting material in the manufacture of x-ray contrast media and other synthetic pharmaceuticals (qv). 

Nickel Salts and Chelates. Nickel salts of simple organic acids can be prepared by reaction of the organic acid and nickel carbonate of nickel hydroxide reaction of the acid and a water solution of a simple nickel salt and, in some cases, reaction of the acid and fine nickel powder or black nickel oxide. 

In industrial production of acid-modified starches, a 40% slurry of normal com starch or waxy maize starch is acidified with hydrochloric or sulfuric acid at 25—55°C. Reaction time is controlled by measuring loss of viscosity and may vary from 6 to 24 hs. For product reproducibiUty, it is necessary to strictly control the type of starch, its concentration, the type of acid and its concentration, the temperature, and time of reaction. Viscosity is plotted versus time, and when the desired amount of thinning is attained the mixture is neutralized with soda ash or dilute sodium hydroxide. The acid-modified starch is then filtered and dried. If the starch is washed with a nonaqueous solvent (89), gelling time is reduced, but such drying is seldom used. Acid treatment may be used in conjunction with preparation of starch ethers (90), cationic starches, or cross-linked starches. Acid treatment of 34 different rice starches has been reported (91), as well as acidic hydrolysis of wheat and com starches followed by hydroxypropylation for the purpose of preparing thin-hoiling and nongelling adhesives (92). 

A number of basic materials such as hydroxides, hydrides and amides of alkaline and alkaline earth metals and metal oxides such as zinc oxide and antimony oxide are useful catalysts for the reaction. Acid ester-exchange catalysts such as boric acid, p-toluene sulphonic acid and zinc chloride are less... 

Diketones 1 can be converted into the salt of an a-hydroxy carboxylic acid upon treatment with alkali hydroxide after acidic workup the free a-hydroxy carboxylic acid 2 is obtained. A well-known example is the rearrangement of benzil (R, R = phenyl) into benzilic acid (2-hydroxy-2,2-diphenyl acetic acid). The substituents should not bear hydrogens a to the carbonyl group, in order to avoid competitive reactions, e.g. the aldol reaction. 

Alkaline Hydrolysis of Kasugamycinic Acid (9a) with Barium Hydroxide. Kasugamycinic acid (250 mg., 0.63 mmole) was hydrolyzed with barium hydroxide-saturated-water at 100°C. for 10 hours, and the reaction mixture was treated in the similar manner as described in the case of alkaline hydrolysis of kasugamycin, affording kasuganobiosamine (4) (179 mg., 0.68 mmole) and barium oxalate (151 mg., 0.62 mmole). 

Any reaction in which a proton is transferred from one substance to another is an acid-base reaction. More specifically, the proton-transfer view is known as the Bronsted-Lowiy definition of acids and bases. In an acid-base reaction, an acid donates a proton, and a base accepts that proton. Any species that can give up a proton to another substance is an acid, and any substance that can accept a proton from another substance is a base. The production of two water molecules from a hydroxide anion (a base) and a hydronium ion (an acid) is just one example of an acid-base reaction acids and bases are abundant in chemistry. 

It will be seen from the various types of leaching reactions given in Table 5.2, that the dissolution of aluminum hydroxide essentially belongs to the chemical process category. The dissolution of the hydroxide in acid or alkali occurs by a mechanism involving neutralization. 

Although organosilanes appear to react slowly (if at all) with water alone, in the presence of acids or bases (e.g., alkali metal hydroxides), reactions to give a silanol and H2 are rapid, with bases being particularly powerful catalysts. The evolution of H2 in this type of reaction may be used as both a qualitative and a quantitative test for Si-H bonds, and the mechanism of the acid and the base hydrolysis has been discussed in detail (30,31). This hydrolytic method is not very common for the preparation of silanols that are to be isolated, because both acids and bases catalyze the condensation of silanols to siloxanes, and therefore, only compounds containing large substituents are conveniently made in this way. If an anhydrous alkali metal salt is used, a metal siloxide may be isolated and subsequently hydrolyzed to give the silanol [Eq. (10)] (32). 

In Sec. 6.4 the reactions of hydroxides and acids were presented. It is possible for an acid with more than one ionizable hydrogen atom (with more than one hydrogen written first in the formula) to... 

The reaction of compound 376 with hydrazine gives product 377 that has been transformed into similar triazoles 378, after reaction with carbon disulfide in the presence of alcoholic potassium hydroxide, benzoic acid in the presence of phosphoms oxychloride, or 3-[bis-(methylthiomethylene)]pentan-2,4-dione and l,l-dicyano-2,2-dimethylthioethylene, in refluxing -butanol (Scheme 40) (Table 55) <2000FES641>. 

Figure 1.4 also shows two other reactions. In reaction 2, ammonia reacts with water to form ammonium hydroxide. Reaction 3 shows that ammonia can also be oxidized to form nitric acid from which all forms of nitrates can be produced. All three forms of nitrogen (ammonia, ammonium hydroxide, and nitrates in various forms) are commonly found in soil and can be added to soil to supply nitrogen to plants (see also Figure 6.5). This process thus opened up an inexpensive method of producing nitrogen compounds that would be used as fertilizers.

This sensitivity to substitution of neutral hydrolysis means that the pH-independent reaction gradually becomes more important than the hydroxide reaction at the high pH end of the region, and becomes much more rapidly more important than acid-catalyzed hydrolysis at low pH. Thus from Fig. 13, the acid-catalyzed reaction can be seen to be significant for the hydrolysis of ethyl acetate between pH 4 and 5, and for phenyl acetate about pH 2 but for 2,4-dinitrophenyl acetate the acid-catalyzed reaction is not detectable at pH 1, and is presumably important only in relatively strong acid. It seems certain that this fast neutral hydrolysis is at any rate a partial explanation for the low efficiency of acid catalysis in the hydrolysis of very weakly basic esters, such as the trifluoroacetates and oxalates, in moderately concentrated acid (see p. 145). 

For example, when sulfonate esters are hydrolyzed with ieO-enriched hydroxide (Reaction 4.38) the product sulfonic acids contain ieO but the starting material recovered after 50 percent reaction does not.75 By the arguments outlined on p. 200 this might be evidence for either a one-step displacement or a two-step mechanism with the first step rate-determining. The latter is made more... 

Esters, on the other hand, are very common hydrolytic precursors to carboxylic acids. The traditional reaction for the hydrolysis of esters is basic saponification using sodium hydroxide or potassium hydroxide. While acid catalysis can also be employed, preparative methods usually use base catalysis because formation of the carboxylate salt drives the reaction to the right and gives high yields of products. 

Acid-base reactions are a special type of double displacement reaction. Acid-base reactions occur when an acid and a base react with one another. An acid is a compound that contains hydrogen and gives off hydrogen ions (H+) when it is dissolved in water. Bases, on the other hand, produce hydroxide ions (OH ) when they are dissolved in water. 

Lactams or related cyclic, conformationally fixed amides are more readily N-alkylated than acyclic amides [96], As illustrated by the examples in Scheme 6.23, structurally elaborate alkylating agents can be used to alkylate lactams. During the workup of such reactions it should be kept in mind that four- and six-membered lactams are readily hydrolyzed by aqueous base (Scheme 3.8), and most lactams are also readily hydrolyzed by aqueous acids. Prolonged treatment of lactams with alkali metal hydroxides or acids during the work-up should therefore be avoided. 

All is not lost however because the periodic acid method is found to be quantitative for the determination of corticosteroid esters, if these are first hydrolysed using a quaternary base, e.g. tetramethylammonium hydroxide. The acidic products formed in the above side-reaction do not perturb the determination, since the optically active product of the periodate oxidation following the hydrolysis is similar to the etianic acid. 

Experimental measurements were carried out in several different solvents by two or three different methods. In some cases a shaking device was used and the rate of the reaction was followed by the evolution of carbon dioxide. In other cases the course of the reaction was followed by titrations using solutions which were sealed off in glass tubes immersed in thermostats and opened up under standardized sodium hydroxide or acid, as the case demanded. Many different tubes of the same solution were sealed off at once and each tube was used for a point on the time-concentration curve. The rate constant was determined from the slope of the line obtained by plotting the logarithm of the concentration against the time. 

Basic acetate-chloroform test Upon dissolving beryllium hydroxide (reaction 1) in glacial acetic acid and evaporating to dryness with a little water, basic berryllium acetate, BeO. 3Be(CH3COO)2, is produced, which dissolves readily upon extraction with chloroform. This forms the basis of a method for separating beryllium from aluminium, since basic aluminium acetate is insoluble in chloroform. The mixed hydroxides are treated as detailed above. 

There is another common way to classify chemical reactions acid-base reactions, oxidation-reduction reactions, and reactions of more complicated types (beyond the scope of this book). Acid-base reactions are considered to involve the reactions of hydrogen ions with hydroxide ions. The reactions of acids and bases will be taken up in this section, and a more sophisticated view of these reactions is presented in Chapter 19. Oxidation-reduction reactions involve the transfer of electrons from one substance to another. Many combination reactions, many decomposition reactions, all single substitution reactions, and all combustion reactions are of this type, but more complex examples are presented in Chapters 16 and 17. 

Violent reaction with alcohols, N-aryl sulfinamides, dimethyl formamide, polychlorobiphenyl, sodium hydroxide, hydrochloric acid + dinitroanilines. Incandescent reaction when warmed with cesium oxide (above 150°), tellurium, arsenic, tungsten dioxide. Potentially dangerous reaction with hydrocarbons + Lewis acids releases toxic and reactive HCl gas. 

Flame-retardants are used as additives in the preparation of fire retardant paints. They are decomposed by heat to produce nonflammable components, which are able to blanket the flames. Both inorganic and organic types of flame-retardants are available in the market. The most widely used inorganic flame-retardants are aluminum trihydroxide, magnesium hydroxide, boric acid, and their derivatives. These substances have a flame-retardant action mainly because of their endothermic decomposition reaction and their dilution effect. The disadvantage of these solids is that they are effective in very high filler loads (normally above 60 percent). 

The number of ml. of 0.1 iV iodine minus the number of ml. of 0.1 N thiosulfate, and the number of ml. of 0.1 N sodium hydroxide minus the number of ml. of 0.1 N hydrochloric acid give the respective quantities of 0.1 A iodine and 0.1 JV sodium hydroxide used in the oxidation of the sugar. One millimole of the sugar (0.15 g. of D-xylose) requires for oxidation 20 ml. of 0.1 N iodine and 30 ml. of 0.1 N sodium hydroxide (reaction 14, page 157). Either iodine or alkali consumed, or both as checks, may be used to calculate the amount of aldose present. 

Methylation of 2-amino-3-hydroxypyrazine (62) with methyl iodide and sodium methoxide afforded 3-amino-l-methyl-2-oxo-1,2-dihydropyrazine (63), and when an excess of methyl iodide was used, a mixture of compound (63) and its methio-dide (64) was isolated. Reaction with dimethyl sulfate and alkaU gave compound (63) and l,4-dimethyl-2,3-dioxo-l,2,3,4-tetrahydropyrazine (66) the latter was presumed to be formed by hydrolysis of an intermediate quaternary salt since it was also obtained by treatment of the methiodide (64) with aqueous sodium hydroxide. Reaction of 2-amino-3-hydroxypyrazine with ethereal diazomethane produced a mixture of N- and 0-methyl derivatives, (63) and 2-amino-3-methoxy-pyrazine (65). With methyl toluene-p-sulfonate the quaternary salt 2-amino-3-hydroxy-1-methylpyrazinium toluenesulfonate (67) was obtained on alkaline hydrolysis it gave 3-hydroxy-l-methyl-2-oxo-l,2-dihydropyrazine (68) (832). Pulcherriminic acid with diazomethane gave a dimethyl derivative (99). 

Esters or ethereal salts are derivatives of alcohols formed by the reaction of an alcohol with an acid. As they are thus acid derivatives also and as the more important esters are those formed from the organic acids, which we shall soon study, the chief discussion of them as a group will come later. There are, however, to be considered the esters formed from inorganic acids and these will be presented now. The chemical properties of alcohol in its relation to both bases and acids are of especial interest and importance. We have spoken of the fact that alcohol as an hydroxyl compound belongs to the water type, and that the other representatives of this type are the metal hydroxides or bases, and the non-metal hydroxides or acids. 

Many of the basic concepts of micellar-polymer flooding apply to alkaline flooding. However, alkaline flooding is fundamentally different because a surfactant is created in the reservoir from the reaction of hydroxide with acidic components in crude oil. This reaction means that the amount of petroleum soap will vary locally as the water-to-oil ratio varies. The amount of petroleum soap has a large effect on phase behavior in crude-oil-alkali-surfactant systems. 

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