Reaction with Water Hydrolysis

Hydrolysis.—(7) Reaction with water hydrolysis. As we have stated in discussing the relation between sulphonic acids and sulphuric acid esters the former do not hydrolyze as do the latter, yielding the acid and alcohol. Hydrolysis may, however, be brought about by the use of steam and the products of such reaction are the hydrocarbon and sulphuric acid. 

In polymers containing ester, amide, or similar functional groups in the main chain, it is possible in principle to split the chain by means of a reaction with water (hydrolysis). Acids and lyes may act as catalysts, whereby chain splitting may be encouraged in hot water in particular, which thus represents the reverse reaction of... 

Add halides are important intermediates and they are used extensively for the conversion of carboxylic adds into other derivatives. For example, add halides can be used to prepare (in addition to amides) anhydrides, esters, aldehydes, and ketones. Add halides readily undergo reaction with water (hydrolysis) to form the corresponding carboxylic add. For this reason the reaction system must be protected from atmospheric moisture when add halides are formed and/or used. 

Mechlorethamine undergoes very rapid reaction with water (hydrolysis) and with other nucleophiles, so much so that within minutes after injection into the body, it has completely reacted. The problem for the chemist, then, was to find a way to decrease the nucleoplulidty of nitrogen while maintaining reasonable water solubility. Substitution of phenyl for methyl... 

Acidity of Amides, Imides, and Sulfonamides Characteristic Reactions Reaction with Water Hydrolysis Reaction with Alcohols Reactions with Ammonia and Amines Reaction of Acid Chiorides with Salts of Carboxylic Acids Interconversion of Functional Derivatives Reactions with Organometallic Compounds 18.10 Reduction... 

However, a number of simple molecular compounds are soluble in water and undergo a chemical reaction with water (hydrolysis) to release ions. The molecular substance is completely or partially converted into ions. Examples of such... 

By the action of concentrate aqueous ammonia solution upon esters. This process is spoken of as ammonolysls of the ester, by analogy with hydrolysis applied to a similar reaction with water. If the amide is soluble in water, e.g., acetamide, it may be isolated by distillation, for example ... 

Alkyl hydrogen sulfates can be converted to alcohols by heating them with water This IS called hydrolysis, because a bond is cleaved by reaction with water It is the oxygen-sulfur bond that is broken when an alkyl hydrogen sulfate undergoes hydrolysis... 

The hydrolysis process, ie, reaction with water, for lime is called slaking and produces hydrated lime, Ca(OH)2. Calcium hydroxide is a strong base but has limited aqueous solubiHty, 0.219 g Ca(OH)2/100 g H2O, and is therefore often used as a suspension. As an alkaH it finds widespread iadustrial appHcatioa because it is cheaper than sodium hydroxide. 

Reaction with Water. The alkyl carbonate esters, especially the lower ones, hydroly2e very slowly in water when compared to the carbonochloridic esters (chloroformates). Under alkaline conditions, the rates of hydrolysis are similar to those of the corresponding acetic acid esters. 

If the intermediate is very unstable, large rate constants may be measured in this way. Thus, Amyes and Jencks studied the hydrolysis of a-azidoethers (Ns", the azide ion, being the common ion), finding (because k i had been independently measured) k2 values in the range 10 to 10 ° M s for the reaction with water. 

Imine formation is reversible. Show all the steps involved in the acid-catalyzed reaction of an imine with water (hydrolysis) to yield an aldehyde or ketone plus primary amine. 

Conversion of Acid Halides into Esters Alcoholysis Acid chlorides react with alcohols to yield esters in a process analogous to their reaction with water to yield acids. In fact, this reaction is probably the most common method for preparing esters in the laboratory. As with hydrolysis, alcoholysis reactions are usually carried out in the presence of pyridine or NaOH to react with the HC1 formed. 

It is interesting to determine which bond (the P—O bond marked a or the O—P bond marked b) is cleaved by hydrolysis (reaction with water). 

An important metabolic reaction of disaccharides is the reverse of (5). Water, in the presence of H+(aq), reacts with sucrose to give glucose and fructose. This process is called hydrolysis, meaning reaction with water."... 

This reaction is an example of a hydrolysis reaction, a reaction with water in which new element-oxygen bonds are formed. Another example is the reaction ot PC15 (phosphorus oxidation state +5) with water to produce phosphoric acid, H3P04 (also phosphorus oxidation state - -5) ... 

Pure parathion is a pale yellow, practically odorless oil, which crystallizes in long white needles melting at 6.0° C. (17). It is soluble in organic solvents, except kerosenes of low aromatic content, and is only slightly soluble in water (15 to 20 p.p.m. at 20° to 25° C.). Peck (35) measured its rate of hydrolysis to diethyl thiophosphate and nitro-phenate ions in alkaline solutions. He found that the reaction kinetics are first order with respect to the ester and to hydroxyl ion. In normal sulfuric acid the rate of hydrolysis was the same as in distilled water. Peck concluded that hydrolysis takes place by two mechanisms—a reaction catalyzed by hydroxyl ions and an independent uncatalyzed reaction with water. He calculated that at a pH below 10 the time for 50% hydrolysis at 25° C. is 120 days in the presence of saturated lime water the time is 8 hours. The over-all velocity constant at 25° C. is k = 0.047 [OH-] + 4 X 10-6 min.-1... 

The bromination and hydrolysis of ketenes and bisketenes have been studied. The reaction of the bis(ketene) 289 with bromine has yielded the dibromo fumarate derivative 290, whose /r/mr-con figuration has been confirmed by X-ray crystallography (Scheme 41).366 The hydrolysis of the dibromo fumarate derivative 291 first provided the dibromo derivative (5//)-furanone 292. The prolonged reaction with water afforded the maleic anhydride 293. The methanolysis of the dibromo fumarate derivative 290 has resulted in the formation of an isomeric mixture of dimethyl... 

We can ignore ions such as Sr2+, which come from strong acids or strong bases in this type of problem. Ions, such as C2H3O2", from a weak acid or a base, weak acid in this case, will undergo hydrolysis, a reaction with water. The acetate ion is the conjugate base of acetic acid (Ka = 1.74 x 10 5). Since acetate is a weak base, this will be a Kb problem, and OH will form. The equilibrium is ... 

Hydrolysis Reactions. Hydrolysis reactions involve cleavage of a single bond by reaction with water, a hydronium, or a hydroxide ion (78). The bond is typically polarized between an electron-deficient atom (C in carbonyl, P in organophosphates) and an electron-rich atom (0, Cl, Br). The reaction may be neutral, base-, or acid-promoted, depending on the substrate properties and the reaction conditions, such as pH, temperature, and ionic strength (78, 79). 

The behavior of a salt will depend upon the acid—base properties of the ions present in the salt. The ions may lead to solutions of the salt being acidic, basic, or neutral. The pH of a solution depends on hydrolysis, a generic term for a variety of reactions with water. Some ions will undergo hydrolysis and this changes the pH. 

The same displacement occurs in the hydrolysis of picrylimidazole238 (103). 103 reacts with n-butylamine in water239 to yield picric acid (from the reaction with water) and N-n-butyl-2,4,6-trinitroaniline. The dependence of k0bs values (s 1 moP1 dm3) on pH values indicates the presence (and importance) of equilibrium 27 on the reaction pathway of the... 

The early sources of phenol were the destructive distillation of coal and the manufacture of methyl alcohol from wood. In both cases, phenol was a by-product. Recovered volumes were limited by whatever was made accidentally in the process. Initial commercial routes to on-purpose phenol involved the reaction of benzene with sulfuric acid (1920), chlorine (1928), or hydrochloric acid (1939) all these were followed by a subsequent hydrolysis step (reaction with water to get the -OH group) to get phenol. These processes required high temperatures and pressures to make the reactions go. They re multistep processes requiring special metallurgy to handle the corrosive mixtures involved. None of these processes is in commercial use today. 

Hydrolysis Reaction with water molecule, which acts as an acid or a base... 

The solubility of some gases, such as CO2, is complicated by their chemical reaction with water. In the case of CO2, these reactions tend to reach equilibrimn rapidly, making the equilibrium concentration of CO2 a function of temperature, salinity, the atmospheric partial pressure of CO2, and pH. The last determines the degree to which CO2 is converted into the other inorganic species, H2C03(aq), HCO3 (aq), and COj Caq). Other gases that react with water include H2S and NH3. Note that these hydrolysis and acid dissociation reactions act to enhance the solubility of the parent gas. 

The nitrile produced in the above reaction can be converted into the corresponding carboxylic acid by acid hydrolysis, l.e. reaction with water catalysed by hydrogen ions from the acid. 

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