Greg E.
  • Member for 9 years, 7 months
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  • Michigan
Rearrangement of a gas law equation
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9 votes

If one rearranges the ideal gas law equation, you can obtain the following (assuming $n$ and $T$ are non-zero): $$\frac{PV}{nT} = R$$ $R$ is a constant, and there are in fact infinitely many ...

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Prediction of products in reaction of dicarbonyl with alpha-haloketone
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Klaus Warzecha has already provided the correct mechanism, but I'd like to offer a supplementary discussion. One approach here would be to attempt to eliminate some of the options based simply on ...

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Selectivity in aldol condensation between pivaldehyde and acetone
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9 votes

Ketones have two alkyl groups attached to the carbonyl moiety, which are electron-donating by hyperconjugation. That is, the overlap of $\ce{C-C}$ and $\ce{C-H}$ $\sigma$-bonds with the $\pi$-type ...

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Exothermic or Endothermic reactions
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As anglinb pointed out, the only completely reliable method of determining whether the reactions are endo- or exothermic is by calculation. That said, certain generalizations may allow reasonable ...

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How does oxygen fight odors? (Deodorant ad)
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8 votes

In my estimation, this is basically marketing nonsense. If you examine the list of ingredients, the primary active agent is invariably some aluminum or aluminum-zirconium salt, which act as anti-...

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Can toluene be oxidized to benzoic acid using Pyridinium Chlorochromate(PCC)?
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8 votes

PCC is generally regarded as a milder oxidizing agent, used to effect selective oxidation of alcohols to aldehydes (from $1^{\circ}$ alcohols) or ketones (from $2^{\circ}$ alcohols). While over-...

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chemically inert molecule with piezoelectric properties
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8 votes

The ur-piezoelectric crystal is quartz. Being composed of $\ce{SiO2}$, it more or less epitomizes chemical/biological inertness. It has the additional advantage of being comparatively cheap and common....

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What is the nature of water?
7 votes

$\ce{H2O}$ is a both a neutral molecule and an amphoteric molecule — the two are not mutually exclusive terms. An amphoteric molecule is simply one that can act as either an acid or a base, ...

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Reaction mechanism for oxidation of primary alcohol to carboxylic acid
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7 votes

A dichromate salt and aqueous sulfuric acid are used to prepare chromic acid in situ, which is among the most powerful oxidizing agents commonly available. A primary alcohol is first oxidized to an ...

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Would dissolving a salt and letting it sit for 48 hours have an effect on the solution?
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7 votes

The only reactions that I would expect to occur to any significant extent with pure water are acid-base reactions between the citrate and water, where water, being amphiprotic, could act as either an ...

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How to calculate the pH of a buffer after HCl was added?
7 votes

For (a), the Henderson-Hasselbalch equation, $$\ce{pH} = \mathrm{p}K_a + \log([\ce{A^{-}}]/[\ce{HA}]),$$ comes in handy. Because your molarities and volumes of the acid and its conjugate base are ...

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Kinetic and Thermodynamic Stability
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7 votes

Chemistry is a field with far too many exceptions and edge cases to be making sweeping categorical statements. There are numerous examples of ionic compounds that are isolable and stable, the ...

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Order of reactivity of carbonyl compounds to Nucleophilic addition reaction
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7 votes

My instinct is that there are probably too many variables here for a definitive and accurate answer to be given strictly from first principles. When comparing molecules in which there is only one key ...

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Is it possible to react two distinct carboxylic acids to form a dicarbonyl ester?
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7 votes

The standard term for such molecules is acid anhydride, as they can be viewed as the product of a condensation reaction between two carboxylic acids, with concomitant loss of $\ce{H2O}$. Asymmetric ...

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Bond of interest
7 votes

In IR, the vibrational frequencies of a simple diatomic molecule can be described by the following equation: $$ \bar\nu = \frac{1}{2\pi c}\sqrt{\frac{k}{\mu}} $$ Here, $k$ is the force constant, $\...

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What are the oxidation states of sulfur in the tetrathionate ion?
7 votes

Consider the structure of tetrathionate. The two central sulfurs each have two lone pairs and are assigned half of the electrons from the two bonds they make, since the electrons of bonds between ...

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A few questions about the conditions of the Diels Alder Reactions
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7 votes

Yes, conjugated dienes can react with other conjugated dienes in Diels-Alder reactions. A well known example of this is the dimerization of cyclopentadiene. All the standard caveats, restrictions, and ...

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Differences between H-H-O and H-O-H
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There is no molecule in existence with the structure H-H-O, for the simple reason that hydrogen possesses only one orbital and is therefore chemically incapable of forming more than one bond or ...

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Boat conformation: axial hydrogens
6 votes

If you want to be very precise (perhaps pedantic), then I would conclude that the question itself is a little dubious without additional clarification. Consider the IUPAC recommendation on Basic ...

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How to add two hydroxy groups to 1,5-diphenylpentan-3-ol with as high as possible yield?
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6 votes

A few possibilities for direct hydroxylation: $\ce{SeO2}$ immediately comes to mind as one potential option; it is well known to selectively oxidize allylic positions to yield alcohols and carbonyl ...

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Do certain cumulated dienes present geometric isomerism?
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6 votes

Properly speaking, these sorts of allenes/cumulated dienes do not exhibit geometric isomerism in the way that alkenes can. Rather, when each of the two respective carbons bear two different ...

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Organic chemistry textbook for self-learning?
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6 votes

I'll provide a rundown of the general organic chemistry textbooks I've studied in detail: Organic Chemistry, David R. Klein: A very solid introductory text. Emphasis is on expediency and development ...

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Database with organic reaction mechanisms (curly arrows)
6 votes

As far as free online resources go, I've found the following useful: Organic Reactions (organic-chemistry.org) Name-reaction.com List of organic reactions (en.wikipedia.org) I would also strongly ...

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Stability of branched alkenes
6 votes

The Z isomer is destabilized by comparison to the E isomer due to steric strain. This is a consequence of the isopropyl groups being on the same side of the double bond in the Z isomer, resulting in ...

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Does the hydrolysis speed increase when more H+ ions are in the solution?
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6 votes

The glycosidic bond of a polysaccharide chain is essentially an acetal moiety, and hydrolysis of acetals proceeds under acid-catalyzed conditions. Hence, the addition of acid, within some ambit of ...

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Why does chlorine undergo disproportionation in alkaline media?
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6 votes

At constant pressure and temperature, the spontaneity of all chemical reactions is controlled by the difference in Gibbs free energy ($\Delta G$), as described by the following equation: $\Delta G = \...

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Why are only sigma bonds used in determining the geometry and bond angle in VSEPR theory? Why aren't pi bonds used?
6 votes

VSEPR is used to predict highly idealized geometries corresponding to Platonic solids or combinations thereof (e.g., the trigonal bipyramidal geometry being essentially the result of fusing two faces ...

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Why are fluorides more reactive in nucleophilic aromatic substitutions than bromides?
6 votes

Fluorine is the most electronegative element, and the fluoride anion is also much smaller and less polarizable than any of the other halogen anions, making its activity much more dependent on solvent ...

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Esterification of a carboxylic acid and the production of water
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6 votes

The mechanism of the reaction doesn't involve the direct exchange of ions in the way that, e.g., a metathesis/double replacement reaction might. Take a careful look at the reaction mechanism from the ...

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Bromination Pathways with alkane, alkene, and alkyne substrates
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5 votes

I wanted to offer some commentary on the points you've enumerated: You mentioned halogenation of alkenes in the presence of $\ce{H2O}$. This reaction is known as halohydrin formation. It's worth ...

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