Equations Potassium hydroxide

Fig. 7. Solubihty of potassium permanganate, in g/L, in water and aqueous potassium hydroxide. Numbers represent KOH concentration in normality. Solubihty can be approximated by the equation log(sol MnO, g/L) = 1.288 + 0.016 T — 0.108 N where Tis temperature in °C and N is the KOH...

Controlled reductions arc also possible with a variety of other reagents m-Trrfluoromethylnitrobenzene is converted to the azoxy derivative with hot potassium hydroxide-methanol [SS] but gives the arrune with hot sodium sulfide-sodium hydroxide solution [iS9] (equation 71)... 

Under more forcing conditions than had been reported earlier [7], penta-fluorophenol, when heated in a strong solution of aqueous potassium hydroxide, gives a respectable yield of tetrafluororesorcinol [5] (equation 9) The process is much less effective with 2,3,5,6-tetrafluorophenol... 

Terminally unsaturated fluonnated alkenoic acids can be obtained from poly-fluorocycloalkenes by reaction with potassium hydroxide m rert-butyl alcohol [24] (equation 26) The use of a tertiary alcohol is critical because primary and secondar y alcohols lead to ethers of the cycloalkenes The use of a polar aprotic solvent such as diglyme generates enols of diketones [26] (equation 27) The compound where... 

Vanous chlorofluoroacetones on reaction with pentafluorophenyllithium give pentalluorophenylchlorofluoro tertiary alcohols [34, which on treatment with alcoholic potassium hydroxide produce epoxides (equation 12)... 

Water adds to the triple bond of perfluorobutylalkynols in refluxing 98% formic acid to give the perfluorobutyl keto alcohol Methanolic potassium hydroxide or prolonged reflux m formic acid converts the keto alcohol to 2,2-dimethyl-5-perfluoropropyl-2,2-dimethylturan-3(2//)-one [2] (equation 3). 

Double dehydrobromination of cis- and tranj-l-(bromodifluoromethyl)-2-bromocyclohexane with potassium hydroxide gives, as the final product, 1 -cyclohexene-1-carboxylic acid as a result of the hydrolysis of the intermediate, 1-cyclohexenecarbonyl fluoride 4 (equation 4)... 

Cyanacetfic Acid, Hyd/rocyanic Acid.—When an aldehyde is treated vdth oyanaoetic acid in the presence of potassium -hydroxide, condensation takes place according to the general equation—... 

Another example of a precipitation reaction is the process that occurs when we mix aqueous solutions of potassium hydroxide (KOH) and iron(III) chloride (FeCl3). A precipitate forms. A list of species present helps us to determine the net ionic equation describing this process ... 

Write the balanced net ionic equation for the reaction of phosphoric acid with an excess of aqueous potassium hydroxide. 

Reaction of the carbanion of chloromethyl phenyl sulphoxide 409 with carbonyl compounds yields the corresponding 0-hydroxy adducts 410 in 68-79% yield. Each of these compounds appears to be a single isomer (equation 242). Treatment of adducts 410 with dilute potassium hydroxide in methanol at room temperature gives the epoxy sulphoxides 411 (equation 243). The ease of this intramolecular displacement of chloride ion contrasts with a great difficulty in displacing chloride ion from chloromethyl phenyl sulphoxide by external nucleophiles . When chloromethyl methyl sulphoxide 412 is reacted with unsymmetrical ketones in the presence of potassium tcrt-butoxide in tert-butanol oxiranes are directly formed as a mixture of diastereoisomers (equation 244). a-Sulphinyl epoxides 413 rearrange to a-sulphinyl aldehydes 414 or ketones, which can be transformed by elimination of sulphenic acid into a, 8-unsaturated aldehydes or ketones (equation 245). The lithium salts (410a) of a-chloro-/ -hydroxyalkyl... 

The subscript after potassium in the chemical formula for potassium sulfate shows that two potassium ions are needed. Potassium sulfate is a salt. When the two equations are put together (as they would occur when the acid and base are mixed together), they represent the double displacement neutralization reaction that occurs between sulfuric acid and potassium hydroxide ... 

In a chemical equation, like the one for the reaction between sulfuric acid and potassium hydroxide, the reactants (the substances being mixed together) are always written on the left-hand side of the equation. The products (the substances made when the reactants react with each other) are placed on the right-hand side of the equation. Atoms cannot be made or destroyed in a chemical reaction, only rearranged. This is called the law of conservation of matter. Therefore, there must always be the same number of atoms of each element on the reactant side of the equation as there are on the product side. 

To build the balanced chemical equation that shows the chemical reaction between sulfuric acid and potassium hydroxide, start off by writing the reactants on the left-hand side of the equation ... 

The extra hydrogen atom on the reactant side of the equation cannot just disappear. Likewise, there cannot be more potassium atoms on the right side of the equation than on the left side. Therefore, sulfuric acid and potassium hydroxide must not react in a 1 1 ratio. Instead, for every molecule of sulfuric acid that reacts, there must be two molecules of potassium hydroxide ... 

Now there are four hydrogen atoms on the reactant side (two in sulfuric acid and one in each of the two molecules of potassium hydroxide) and four hydrogen atoms on the product side (two in each of the two molecules of water). All of the other atoms have equal numbers on each side as well. Now the equation conforms to the law of conservation of matter, and it is a balanced chemical equation. 

An alternative procedure, again using microwave irradiation but in the presence of aqueous potassium hydroxide and silica, caused cyclization of semicarbazide derivatives 185 to give 3-mercapto-l,2,4-triazoles 186a-f in high yields (Equation 58 and Table 39) <2006PS(181)1839>. 

In the case of 2-amino-1,3,4-oxadiazoles, an external N-nucleophile is not necessary for their conversion into the corresponding triazole derivatives the reaction occurred in ethanol in the presence of potassium hydroxide (Equation 5) <2003BML769>. 

Treatment of 1-pyridinium sulphonate with sodium or potassium hydroxide generates sodium or potassium salts of 5-hydroxy-2,4-pentadienal (glutaconaldehyde), which are starting materials for a variety of transformations (equation 178)171b 301. For example, the reaction of the potassium salt with a carbon electrophile has been used for the preparation of a dienol aldehyde (equation 179)mb which was an intermediate in the total synthesis of a mutagen, (S)-3-(dodeca-l,3,5,7,9-pentaenyloxy)propane-l,2-diol. 

Give the equation for the reaction between 2-bromo-3-methylbutane and dilute aqueous potassium hydroxide. What are the conditions for the reaction (3)... 

A—Acetic acid is a weak acid as such it should appear as HC2H302. Potassium hydroxide is a strong base so it will separate into K+ and OH ions. The potassium ion is a spectator ion, and is left out of the net ionic equation. 

Alkyl halides are converted into the tertiary amines RNMe2 (R = Me, Et, Bu, PI1CH2, CH=CCH2 etc.) by the action of acetaldehyde /V,/V-dirnethylhydrazone, followed by hydrolysis of the product with methanolic potassium hydroxide (equation 13)43. 

The oxidative deamination of primary and secondary amines is accomplished efficiently by treatment with 3-trifluoromethylbenzenesulphonyl peroxide (ArS02)202 (Ar = 3-F3CC6H4) in ethyl acetate, followed by powered potassium hydroxide at — 78 °C and finally water (equation 86). 

A student uses a coffee-cup calorimeter to determine the enthalpy of reaction for hydrobromic acid and potassium hydroxide. The student mixes 100.0 mL of 0.50 mol/L HBpaq) at 21.0°C with 100.0 mL of 0.50 mol/L KOH(aq), also at 21.0°C. The highest temperature that is reached is 24.4°C. Write a thermochemical equation for the reaction. 

Thioureas (25) rearrange spontaneously at room temperature to thiadiazoles (26) (Scheme 9) (77JCS(P1)1616>. In contrast, the corresponding ureas (27) require refluxing in aqueous potassium hydroxide in order to be transformed into the triazolones (28) (Equation (8)) <90JCS(P2)1289>. 

If the fragmentation of the alkoxide is rate-determining and endothermic, one would expect the transition state structure to resemble the products and thence be influenced by the relative stability of the carbonyl fragment. A transformation similar to the retroaldol cleavage of B-hydroxynitrosamines has been observed. Kruger reported that the treatment of 2-ketopropylpropylnitrosa-mine with refluxing potassium hydroxide in alcohol led to the production of methyl propylnitrosamine as is illustrated in equation 6 (10). This transformation is also under study in our laboratory. 

Only very powerful nucleophilic reagents such as HO-, NHJ, RLi, LAH, etc., react effectively at the ring carbon atoms of simple pyridines (c/. equation 22), and even then forcing conditions may be required. Oxidation of pyridine to 2-pyridone with potassium hydroxide, for example, requires a temperature of ca. 300 °C. Nevertheless, some of these reactions can be of very considerable synthetic importance, especially the classical Chichibabin reaction for the preparation of 2-amino, alkylamino and hydrazino heterocycles (equation 28). The sequence of substitution is C-2, then C-6 and finally C-4. The Chichibabin reaction also requires rather vigorous conditions and often proceeds in only moderate yield the simplicity of the approach, however, is such that it often represents the method of choice for the preparation of the requisite substituted heterocycle. 

Potassium hydroxide-mediated elimination of cyanoethylene from the 4-cyanoethyltriazoloozadiazole 131 yielded the potassium salt 68 (Equation 6) <1996TL8577>. 

Alkylation of pyrano[2,3-z7]-l,2,3-triazine 203 with a number of electrophiles in 15% potassium hydroxide/acetone solution gave the substituted triazines 204 in a remarkably consistent 55% yield (Equation 18) <2003MI1061>. 

The most common method used to synthesize the diazafluorenes is by alkaline oxidation of phenanthrolines <1996CHEC-II(7)921>. For example, Gusak a a/, have shown that compounds such as 87 can be converted into the corresponding diazafluorenones using potassium hydroxide and potassium permanganate (Equation 23) <2004RJ01322>. 

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