Skeletal equation

Note that the soHds density used ia this equation should be the tme soHds, ie, skeletal, density, because the gas ia the pores is also compressed. For Group A soHds the aeration gas should also be added evenly along the standpipe. 

Skeletal rearrangements in volving a ring size change are observed in reactions of DAST with some cyclic alcohols [131, 134, 755] (equations 69 and 70). 

Trimethylacetaldehyde reacts with sulfur tetrafluoride with a skeletal rearrangement 2,3-difluoro-2-methylbutane is formed in high yield as the only fluo-roalkane along with bis(l-fluoro-2,2-dimethylpropyl) ether [169] (equation 85)... 

Hexafluoroacetone azine accepts nucleophiles (ROH, RSH, R NH) in positions 1 and 2 to yield hydrazones [27] Phosphites give open-chain products via a skeletal rearrangement [22] Radical addition reactions are also reported [22] Treatment of tnfluoropyruvates with tosylhydrazine and phosphorus oxychlo-ride-pyndme yields tnfluoromethyl-substituted diazo compounds [24] (equation 3)... 

Because of Us high polarity and low nucleophilicity, a trifluoroacetic acid medium is usually used for the investigation of such carbocationic processes as solvolysis, protonation of alkenes, skeletal rearrangements, and hydride shifts [22-24] It also has been used for several synthetically useful reachons, such as electrophilic aromatic substitution [25], reductions [26, 27], and oxidations [28] Trifluoroacetic acid is a good medium for the nitration of aromatic compounds Nitration of benzene or toluene with sodium nitrate in trifluoroacetic acid is almost quantitative after 4 h at room temperature [25] Under these conditions, toluene gives the usual mixture of mononitrotoluenes in an o m p ratio of 61 6 2 6 35 8 A trifluoroacetic acid medium can be used for the reduction of acids, ketones, and alcohols with sodium borohydnde [26] or triethylsilane [27] Diary Iketones are smoothly reduced by sodium borohydnde in trifluoroacetic acid to diarylmethanes (equation 13)... 

Mercury(II) trifluoroacetate is a good electrophile that is highly reactive toward carbon-carbon double bonds [52, 53, 54] When reacting with olefins in nucleophilic solvents, it usually gives exclusively mercurated solvoadducts, but never products of skeletal rearrangement Solvomercuration-demercuratton of alkenes with mercury(II) trifluoroacetate is a remarkably effective procedure for the preparation of esters and alcohols with Markovnikov s regiochemistry [52, 5J] (equation 24)... 

Triflic acid is strong enough to protonate polycyclic saturated hydrocarbons [77, 78, 79], and even -butane [80, 81], and to initiate skeletal rearrangements Acidic treatment of homoadamantane [77] (equation 32), 2-homoprotoadamantane [78] (equation 33), or as 2,3-trimethylenebicyclo[3 3 Ojoctane [79] (equation 34) causes their rearrangement to isomenc hydrocarbons... 

Both benzothieno[3,2-b]pyridine 5-oxide (31) and thieno[3,2-b 4,5-b ]dipyridine 5-oxide (32) exhibit competitive loss of oxygen either as an atom or as carbon monoxide after initial skeletal rearrangement, e.g. to sulfenate esters (equation 10)18b. These results together with some data for Y-oxides indicate that the presence of an intense [M — 16] + peak is not diagnostic for the latter only. 

This expression is called a skeletal equation because it shows the bare bones of the reaction (the identities of the reactants and products) in terms of chemical formulas. A skeletal equation is a qualitative summary of a chemical reaction. 

Because atoms are neither created nor destroyed, chemists regard each elemental symbol as representing one atom of the element (with the subscripts giving the number of each type of atom in a formula) and then multiply formulas by factors to show the same numbers of atoms of each element on both sides of the arrow. The resulting expression is said to be balanced and is called a chemical equation. For example, there are two H atoms on the left of the preceding skeletal equation but three H atoms on the right. So, we rewrite the expression as... 

In some cases, the stoichiometric coefficients needed to balance an equation are easy to determine. For example, let s consider the reaction in which hydrogen and oxygen gases combine to form water. We start by summarizing the qualitative information as a skeletal equation ... 

We use the international Hazard road sign A to warn that a skeletal equation is not balanced. Then we balance hydrogen and oxygen atoms ... 

An equation must never be balanced by changing the subscripts in the chemical formulas. That change would imply that different substances were taking part in the reaction. For example, changing H20 to H202 in the skeletal equation and writing... 

Sometimes we need to construct a balanced chemical equation from the description of a reaction. For example, methane, CH4, is the principal ingredient of natural gas (Fig. H.3). It burns in oxygen to form carbon dioxide and water, both formed initially as gases. To write the balanced equation for the reaction, we first write the skeletal equation ... 

STRATEGY First write the skeletal equation. Balance first the element that occurs in the fewest formulas. Verify that the coefficients are the smallest whole numbers. Specify the states of each reactant and product. 

K.l Write a balanced equation for each of the following skeletal redox reactions ... 

A rocket fuel would be useless if its oxidation were not spontaneous. Although rockets operate under conditions that are far from standard, an initial estimation of the potential of a rocket fuel might assess whether its oxidation at the high temperatures reached in a rocket is spontaneous. A chemist exploring potential fuels for use in space considered using vaporized aluminum chloride in a reaction for which the skeletal equation is... 

Step 2 Write the two skeletal (unbalanced) equations for the oxidation and reduction half-reactions. 

Permanganate ions, Mn04, react with oxalic acid, H2C204, in acidic aqueous solution, producing manganese(II) ions and carbon dioxide. The skeletal equation is... 

Step 2 Write the skeletal equation for Mn04 —> Mn02... 

Balance each of the following skeletal equations by using oxidation and reduction half-reactions. All the reactions take place in acidic solution. Identify the oxidizing agent and reducing agent in each reaction. 

Balance the following skeletal equations and classify them as acid-base or redox ... 

Balance each of the following skeletal equations and classify the reaction as Bronstcd-I. owry acid-base, Ix wis acid-base, or redox. For both types of acid-base reactions, identify the acid and the base. For redox reactions, identify the reducing agent and the oxidizing agent. 

Predict the major products of each of the following reactions and then balance the skeletal equations ... 

Because the complexes listed in Tables 1-8 are all prepared with metal halides and carborane anions, only one example for each type of metallocarborane (number of B atoms) is given in the following representative equations for clarity, the skeletal framework in the equations have numbered positions and H atoms are omitted ... 

In the application of the extended Hammett equation to the system XGY, where X is a substituent and Y is a reaction site, both of which are attached to the skeletal group G, the question of the degree of transmission of substituent effects through G arises. The transmitivity of G is measured by the magnitude of a and (3. Now,... 

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