CHM
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Michael reaction or nucleophilic attack at the alpha carbon of an alpha-beta-unsaturated ketone?
Accepted answer
23 votes

An $\alpha,\beta$-unsaturated ketone is electrodeficient at the $\beta$ position. This can be seen if you draw the resonance structures of such a molecule. The $\beta$ carbon is thus a good site for ...

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How to identify zero order reactions?
17 votes

Determining the rate of the kinetics of a reaction isn't done with only one measurement, or looking at only one graph. What zero order kinetics means, is that the rate of the reaction is independent ...

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Why are arenes with conjoined benzene rings drawn as they are?
16 votes

Both ways of drawing benzene should mean the same thing to you. Use one or the other depending on what you want to express. The Kekulé structure, B, is more useful when you're interested in a ...

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How do you separate enantiomers?
14 votes

The physicochemical properties of enantiomers being the same (except for optical activity), one needs to make use of the chirality of the molecules to separate them. This is done by asymmetrizing the ...

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How do I determine the absolute configuration experimentally?
13 votes

If your compound has been synthesized before, you can measure its optical activity and compare it with the data in the literature. If your compound hasn't been synthesized before, it can be possible ...

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How do orbitals coexist with a nucleus?
12 votes

The $\mathrm{p}$ orbitals, for example, have a nodal plane where the nucleus is, which means the electron density is zero there. An orbital doesn't represent a path the electrons take when moving. An ...

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Why is the 2s orbital lower in energy than the 2p orbital when the electrons in 2s are usually farther from the nucleus?
11 votes

This is not a thorough answer. It holds when comparing orbital energies of the same shell number $n$ (in your case 2) in atoms containing a low number of electrons. This question contains more ...

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Temperature of pure oxygen combustion
9 votes

Oxygen is not a fuel by itself, it's only the oxidant. Combustion involves a fuel (acetylene, for example) and an oxidizer (here, O2). So if you have no fuel, but all oxidizer, then what's left to ...

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Reaction between silver nitrate and aluminum chloride
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9 votes

Le Châtelier's principle only states that a system previously at equilibrium will want to stay at equilibrium - that is, if we perturb it, it will try to go back to equilibrium. This system is ...

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How to understand this form of writing the solution: (some salt • n H₂O)?
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8 votes

The salt's crystal lattice's repeating unit is constituted of n molecules of salt and m molecules of water. Such salts are called hydrates. Wikipedia even has a nice picture of a hydrated vs non ...

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What does the charge distribution around a Stone-Wales defect look like?
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7 votes

FWIW, here are some Hückel calculations on the 5775 PAH. I'm showing the first 7 energy levels. Each molecular graph presents the contribution of each atom to the electron density ($\mathrm{Abs}[c_i]^...

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How can one optimise the formation of copper acetate?
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6 votes

Your question and title do not correspond, IMHO. I'll answer one of both: Vinegar is mostly water, with some acetic acid ($5\%$). A classic experiment, performed by a lot of kids at school, is to mix ...

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How does hot tub "shock" work?
5 votes

There are several properties you can infer from the compound's name. The compound is ionic, which the structure cation [...]-ate informs us. In this case, we're dealing with the potassium salt of ...

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67 failures at extracting acetaminophen from Excedrin(R)
5 votes

Here's what I suggest: Mash up the pills in a mortar Dissolve the powder in cold distilled water, use a beaker Shake well Put the beaker in a freezer and wait until right before the water freezes to ...

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Why does the sulfone ring in tazobactam open when the lactam is hydrolyzed?
5 votes

Here's a draft: First, read this paper. Considering we're under alkaline conditions (blood pH between 7.35-7.45) we'll take their alkaline mechanism proposal. Mechanism This is obviously incomplete, ...

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Why must an oxidizer not touch rubber?
4 votes

A lot of rubbers possess C=C double bonds. Alkenes are very easily oxidized by KMnO4 or KClO3, therefore in the case where you're not aware of the chemical nature of the rubber, it's best not to ...

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Why does gum get harder to chew after a while?
4 votes

I would be surprised if there was reticulation of the gum's polymers upon contact with your saliva. According to this manufacturer, plasticizers are used, and the plasticizers appear to be fats. This ...

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Reaction of soap with water
3 votes

While this question should get a more elaborate answer, mine will at least give you leads. Soaps act as surfactants, that is, they are amphiphilic (both hydrophobic and hydrophilic) molecules that ...

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Can caffeine be separated from coffee?
Accepted answer
2 votes

Regarding "completely": The short answer is no. But for all intents and purposes, yes. By submitting coffee to several small volume extractions, one can drastically reduce the concentration of ...

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A quick method for separating liquids?
0 votes

The only thing that comes to my mind is laminar flow. Watch this video and tell me if that's something like what you're look for. Problem is, you're not really separating "three liquids"...

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What makes diazo compounds so unstable and explosive?
-2 votes

Very short answer: $\Delta G = \Delta H - T\Delta S$ As this is an org-chem question, no need to solve the equation numerically. As you might know, $\ce{N2_{(g)}}$'s standard formation enthalpy ($\...

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