Ionic hydrogenation carbonic acid

C04-0032. Carbonic acid, H2 CO3 (molecular model shown below), is a weak oxoacid that forms when carbon dioxide dissolves in water. Carbonic acid contains two acidic hydrogen atoms. Write the net ionic reaction that occurs when carbonic acid reacts with an excess of hydroxide ions. Draw a molecular picture of the process. 

Please pass the sodium chloride It is amazing that food is seasoned with an ionic compound that is composed of two deadly elements— sodium and chlorine. The gain or loss of electrons can make a big difference in properties. Reacting sodium hydrogen carbonate, which is baking soda, with hydrochloric acid (HCI), the acid found in your stomach, produces salt, carbon dioxide, and water, according to the following equation ... 

Alkenes to Alkanes. The ionic hydrogenation of many compounds containing carbon-carbon double bonds is effected with the aid of strong acids and organosilicon hydrides following the n-route outlined in Eq. 2. A number of factors are important to the successful application of this method. These include the degree and type of substituents located around the double bond as well as the nature and concentrations of the acid and the organosilicon hydride and the reaction conditions that are employed. 

The use of deuterated organosilicon hydrides in conjunction with proton acids permits the synthesis of site-specific deuterium-labeled compounds.59 126 221 Under such conditions, the deuterium atom in the final product is located at the charge center of the ultimate carbocation intermediate (Eq. 62). With the proper choice of a deuterated acid and organosilicon hydride, it may be possible to use ionic hydrogenation in a versatile manner to give products with a single deuterium at either carbon of the original double bond, or with deuterium atoms at both carbon centers.127... 

Protonated carbonic acid (fFCCF-1-, 175) is recognized as a stable species in superacids and even a salt was isolated with its X-ray crystal structure obtained. In strong superacids, diprotonated carbonic acid (30) was found to undergo ionic hydrogenation to methane (eq 45).77... 

Name acid salts as ionic compounds, but put the word hydrogen in the name of the anion (perhaps with a prefix) to indicate that at least one ionizable hydrogen atom is still present. For example, NaHCOs is sodium hydrogen carbonate. (Section 6.3)... 

Net ionic equations can also be written for reactions in which gases are produced. For example, sodium hydrogen carbonate reacts with nitric acid to produce sodium nitrate, carbon dioxide, and water ... 

Although hydrosilanes reduce ketones, in trifluoroacetic acid, to the corresponding methylene compounds or dimeric ethers via ionic hydrogenation, the reduction of a-amino and a-oxy ketones and p-keto acid derivatives with hydrosilanes, particularly PhMe2SiH, under these conditions proceeded with high anti selectivity to the alcohols. No racemization was observed at the carbon a to the carbonyl group. Intramolecular hydrosilylation catalyzed by Lewis acids provided a highly stereoselective route to anti-1,3-diols from p-hydroxy ketones (Section 1.1.3. ). ... 

The rate-determining step in the ionic hydrogenation reaction of carbon-carbon double bonds involves protonation of the C==C to form a carbocation intermediate, followed by the rapid abstraction of hydride from the hydride source (equation 45). ° There is a very sensitive balance between several factors in order for this reaction to be successful. The proton source must be sufficiently acidic to protonate the C—C to form the intermediate carbocation, yet not so acidic or electrophilic as to react with the hydride source to produce hydrogen. In addition, the carbocation must be sufficiently electrophilic to abstract the hydride from the hydride source, yet not react with any other nucleophile source present, i.e. the conjugate anion of the proton source. This balance is accomplished by the use of trifluoroacetic acid as the proton source, and an alkylsilane as the hydride source. The alkene must be capable of undergoing protonation by trifluoroacetic acid, which effectively limits the reaction to those alkenes capable of forming a tertiary or aryl-substituted carbocation. This essentially limits the application of this reaction to the reduction of tri- and tetra-substituted alkenes, and aryl-substituted alkenes. 

The ionic hydrogenation of carbon-carbon multiple bonds has been demonstrated only for the reduction of carbon-carbon double bonds which on protonation result in the formation of tertiary, or aryl-substituted, carbocations. The ability to use this reduction reaction with functionally substituted alkenes will be limited to those systems that do not contain functional groups that would otherwise react with trifluo-roacetic acid or the organosilane. 

There has been no report on the success, or failure, of the attempted reduction of (Z C bonds by the ionic hydrogenation type of reaction. The reason for this is not clear. Carbon-carbon triple bonds are capable of being protonated by trifluoroacetic acid to produce what appear to be vinyl cationic species, which should be capable of abstracting a hydride from an organosilane. 

A reaction occnrs when nitric acid (HNO3) is mixed with an aqneons solntion of potassinm hydrogen carbonate. Aqneons potassium nitrate is produced. Write the chemical and net ionic eqnations for the reaction. 

Gas-phase studies have been made to gain information about the intrinsic stability of hydrogen-bonded ionic intermediates of alcohols and carbon acids. Many anionic hydrogen-bonded complexes appear to be better when there is a good match of the gas-phase acidities of a neutral and the conjugate acid of the ion. 

Reactions of Arrhenius Acids and Ionic Compounds Containing Carbonate or Hydrogen Carbonate... 

The reaction between an acid and an ionic compound containing either carbonate or hydrogen carbonate leads to carbon dioxide and water as products. The addition of Fi ions to C03 or FiC03 forms carbonic acid, Fi2C03. Carbonic acid, however, is unstable in water, so when it forms, it decomposes into carbon dioxide, C02( )> and water, Fi20(/). 

Given the names or formulas for a monoprotic or polyprotic acid and an ionic compound containing hydroxide, carbonate, or hydrogen carbonate ions, write the complete balanced equation that describes the neutralization reaction that takes place between them. 

As with the similarly polarized boron and aluminium hydrides, hydrido-silanes can transfer formal hydride ions to electropositive carbon centres. Unlike the first two reducing agents, hydridosilanes require additional activation of the carbon centre by Lewis or protic acids before such hydride transfer can take place. This overall process is known as ionic hydrogenation (4). The reagent system of triethylsilane and boron trifluoride etherate has provided an extremely selective method for the reductive deoxygenation of lactols (5), derived in turn from DIBAL reduction (6) of the corresponding y- or 6-lactones ... 

In natural waters with the main protolytic system of carbon dioxide and its ionic forms, the determination of acid capacity up to pH 4.5 (ANC4 5) (so-called alkalinity) is the most important from the analytical viewpoint in this case hydrogen carbonates react to form free CO2 ... 

The acid consumption corresponds to the content of hydrogen carbonates. As well as free HCO3 ions, hydrogen carbonate complexes bonded in ionic pairs with calcium, magnesium, etc. are also determined. 

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