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## Hot answers tagged experimental-chemistry

4

The Horwitz function 1, also known as the Horwitz “Trumpet”, is an empirical relationship that has, thus far, not been derivable from fundamental principles. As noted by Thompson 2, and as shown below in Fig. 1 (from 2), the relative standard deviation of reproducibility (RSDR) increases as analyte concentration decreases: Horwitz formulated his expression ...

3

I can provide some physical intuition, but it's still going to require math and previous work to make it happen (aside on this at the end). Let's consider a particle in just one dimension. There are two quantities of interest: (1) the position of the particle along this coordinate, (2) the scalar momentum (related to the velocity) along this coordinate. I'...

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Formic acid is volatile. Any volatile liquid, including water, if heated ( externally or spontaneously in mixture ) forms fumes, if temperature in gas above the liquid drops below its dew point. Remember water "fumes" over a boiling kettle. Additionally to these physical-chemical reasons, if there is boiling (or other strong mechanical disturbance) ...

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It would be extremely dangerous to use a flammable solvent for a heat bath because any spill on the hot plate (or even worse, a Bunsen burner) could cause a fire. If you want to distill off ether, it is by far better to just use warm water from a tap or a kettle, and replace your hot bath regularly. Trust me, ether can spontaneously catch fire VERY easily !...

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I can't tell you precisely where your reasoning starts to be wrong, but here is another way to think about the problem. Notice that for a specific reaction as you gave here, the term $rV$ is always the same independently of the molecule you choose to determine it. It does vary for sure over time though (don't read I said it was a constant). As you wrote: $... 1 As you can see from figures in Zhe's answer that it is possible by adding waves to make a wavepacket. The characteristic of a wave is that superpositions are possible and these lead to interference/diffraction phenomena. By analysing the wavepacket's spread in wavelength and position, the expression$\Delta k.\Delta x \ge 1$is found where$k=2\pi/\lambda\$. ...

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There is a simple way to understand this if you understand the relationship between frequency and wavelength in a vibrating string But you can't avoid at least some mathematics. They key to understanding where the position momentum uncertainly relationship comes from is to think about the relationship between the frequencies present in a musical note and ...

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It's simply a consequence of wave mechanics and operators. Any observable, i.e., any observable which can be measured in a physical experiment should be associated with a quantum-mechanical operator (like + or - operators, just more complicated). Furthermore, if these operators are intrinsically non-communicative, or if the order in which they are applied ...

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It appears that Sørensen was the first to publish the synthesis of trioxalatocobaltate(III) trihydrate [1]. A summary written in English (and that should answer both of your questions) including chemical reactions can be found in the very first volume of Inorganic Syntheses1 [2, p. 37]: C. POTASSIUM TRIOXALATOCOBALTIATE $$\ce{K3[Co(C2O4)3]·3H2O}$$ ...

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Most alkaloids are tertiary amines. Almost all tests for alkaloids, reagents of which are are solutions of the salts of heavy metals, are precipitation tests. For example, all of tests with Dragendorff's reagent, Mayer's reagent, Hager's reagent, and Wagner's reagent give color precipitates: The heavy metal atom in the reagent with the nitrogen in the ...

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