# Tag Info

## Hot answers tagged experimental-chemistry

5

The Suzuki coupling reaction (also called Suzuki-Miyaura coupling reactions; Ref.1) is the coupling of an aryl or vinyl boronic acid with an aryl or vinyl halide or triflate using a palladium(0) catalyst similar to Heck reaction and Negishi reactions in mechanistic aspects. In particular, Negishi reaction uses organozinc reagents instead of organoboronic ...

3

Aluminum oxide does not react with sulphates, even at high temperature. Anyway, aluminum sulphate does not support high temperatures : it is easily decomposed at around 700°C.

3

I offer the following thoughts on the paper you cite regarding the formation of artemisinin 9 from carboxylic acid 1. You are correct that the allylic hydroperoxide 2 is formed by an ene reaction with singlet oxygen (1O2). The stereochemistry of the hydroperoxide group is the result of the ene reaction occurring on the convex face of the unsaturated cis-...

2

I just looked in the literature, and it has been done even without catalyst in a "reactive distillation column" at high temperatures (patent US201113194873). If you can remove the water formed, you can technically drive the reaction forward, even if it is slow. A catalyst will just make that process easier, requiring less heat and time. Phosphoric acid is a ...

1

It seems the most used way is reaction of sulphuric acid with salts of volatile mineral acids : $$\ce{H2SO4 + NaCl -> NaHSO4 + HCl ^}$$ Reaction with excess of the acid $$\ce{H2SO4 + NaOH ->[H2SO4] NaHSO4 +H2O}$$ has several drawbacks: It is much more exothermic than the former one It releases extra water It needs somewhat diluted solution not to ...

1

Note that the equation $$pV=nRT$$ is valid for a gas only ( more exactly an ideal gas), not for a liquid . Liquid $$\frac nt = \frac {V}{t} \cdot \frac{\rho }{ M}$$ Beware of the proper units. Instead of standard ones, these are more suitable for liquids: $$\mathrm{[mol / s] = [ mL / s ] \cdot \frac {[g/mL]}{[g/mol]}}$$ Gas \frac nt = \frac {V}{t} \...

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Find some nice instruction: http://nzetc.victoria.ac.nz/tm/scholarly/tei-Bio06Tuat03-t1-body-d2.html As Picric Acid stored under layer of water, we could know it's concentration in the water. It should be enough for most of the applications. Temperature ° C. grams picric acid/100 grams solution 0 | 0.67 10 | 0.80 20 | 1.10 30 | 1.38

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If accuracy is not essential, weigh a small amount drained for a fixed time but still wet, and then weigh again dried, to find the ratio of wet-to-dry weight (carefully disposing the dried, sensitized, explosive without destroying the scale or personnel). Though this could give a rough idea of the actual dried weight, it would vary from batch to batch and ...

1

Lyophobic means solvent-hating, and here the solvent is water, so the lyophobic ends (presumably the tails, if we are discussing a normal detergent) will associate to form the hydrophobic core of the micelles. The headgroups meanwhile will preferentially interact with water, forming an interface between solvent and core. If you add detergent to a solution ...

1

You might try a solution of cobalt(II) chloride, $\ce{CoCl2}$, in plain water (which might freeze) or in a mixture of water and ethanol or water and isopropyl alcohol. At some concentration, which you'd experimentally determine, it should turn from pink to blue on cooling to 273 K. See Flinn Scientific's site for more details. BTW, you might as well use ...

1

It's not an all-or-nothing situation, where either we can reliably prediction reaction products, or we have not tried to. For instance, drug companies, for many years, have been making extensive use of increasingly powerful, sophisticated, and refined in silico predictive models to choose likely candidates for in vitro testing. And I would be surprised ...

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