mississippichem

UV-vis spectrometers are useful for quantitative determination of chemical species present in solution. It works best for metal complexes, and highly conjugated organics (chemicals with lots non-cumulated pi bonds). I use one quite frequently myself. They can also be used to help a chemist identify which molecular electronic transitions are allowed, and to assign term symbols to these transitions.

Generally speaking they absorb many frequencies of narrow bands. IR radiation is around the energy of molecular vibrations so molecules with more vibrational degrees of freedom (this depends on the molecular geometry) will have more modes of infrared absorption. Carbon dioxide is a linear molecule so will have fewer unique vibrational degrees of freedom than for example methane. To be observable, that vibrational degree of freedom must result in a net dipole moment change for the molecule.

Hmm...trying to narrow this down. Does this have anything to do with a thermodynamic potential function like Gibbs energy, Hemholtz energy, or maybe even the grand potential? Or is it some spectral phenomenon like Captain Panic mentioned?

Activity?

(1) Katsnelson, M. I.; Novoselov, K. S. Solid State Communications 2007, 143, 3. (2) Vozmediano, M. A. H.; Katsnelson, M. I.; Guinea, F.Physics Reports 2010, 496, 109. If you don't have access to these journals send me a PM. I believe the second paper may be just what you are looking for.

No, my comment is completely relevant. I'm saying that you can't make physics work with aether, the premise is flawed right from the start.

But it had been exhaustively demonstrated that established physics based on both theory and observation does work with aether.

Definitely. Another good example are permanganates, which are purple due to a ligand to metal charge transfer band (or maybe metal to ligand...), a phenomenon not understandable by group theory operations. The group theory is invaluable to those chemists interested in excited states and how they arise in electrochemistry.

I know I give rep based on the quality of the argument, or I try to at least. Its not possible for me to totally distance myself from my own opinion or knowledge (sometimes lack of). In politics I often disagree with people but rep their sound logic. Science is a bit more cut and dry, for me at least (a post with agreeable logic usually yields an agreement).

I wouldn't worry too much. The Bronstead and Lewis definitions are much more broad and useful anyway. The Arrenhius definition is by far the most narrow of the commonly used acid/base theories.

Might I ask why you post in purple? It is not so easy on the eyes.

Okay thanks. Care to elaborate on what you mean by "considered range" and "active range"?

Care to elaborate? There is some current research into developing gold complexes to treat rheumatism, but I'm not aware of any gold-metallo-drugs that are used to treat any gender specific condition. Just because I haven't heard of it doesn't mean it doesn't exist though.

As of current we can only produce antimatter at a very slow rate in a very slow, expensive, and inefficient process. To isolate and contain even a kilogram of antimatter would be an enormous victory at this point .

High energy photons can cause abnormal base pairing in DNA. Adenine usually pairs with thymine, but high energy radiation can cause a thymine-thymine pairing to occur. I'm not a biologist so Im not sure what biological consequences that may have, and this is just one example of many.

Show us. So far this thread has been a great example of what happens when the mathematics is left out of physics. We are left with a bunch of people babbling about their non sense pet theories without offering any proof. The fact that you can watch Pincho Paxton's video and are able to take it seriously is indicative of your lack of physics knowledge. MOND, though probably false, would be a drastic improvement to this thread.

Oh okay. Well equilibrium constants always work, but in this case you can evoke the "leveling effect". Essentially no species that is more acidic than the solvent's conjugate acid can exist in that solvent. Likewise no species more basic than the solvent's conjugate base can exist in that solvent (btw, when I say "exist" I mean to have an appreciable lifetime or to constitute a large part of the solution mole fraction at equilibrium). [ce]NH_{2}^-[/ce] is more basic than the hydroxide anion so will not be a product.

Look up [imath] pK_a [/imath] values for water and ammonia. I know the answer but want you to find it for yourself.

Which species has a lower [imath] pK_a [/imath]? That one tends to be de-protonated at equilibrium, and is therefore the acid on the reactant side.

Draw the hybrids between the AOs and MOs. Remember that hybrids don't really "exist". They represent the linear combinations of AOs that are then mixed to form the ground state MO. MO diagrams can be tough even for a relatively simple heteronuclear diatomic if the amount of orbital overlap is to be considered (which IMO would negate the usefulness of hybrids). Personally I think it is a bit misleading to include hybrids in the traditional "step" MO diagram but this sounds like homework and you've no control over that.

Every junction of lines you see is a carbon atom. Carbon is 4-valent. Add up the carbons and hydrogens...this shouldn't be difficult.

Transmutation of metals doesn't happen by any chemical process. Only nuclear fission and fusion. Alchemy has been a dead art for at least four centuries now. Your efforts are much better spent in real chemistry.

Sorry for insulting your credentials. As a chemist though, you realize that an amateur could seriously injure himself. I'm sure there are some legitimate hobbyists out there who may even have some spec equipment. However we get a lot of people here on this site who don't have enough knowledge to be doing any chemistry safely at home, many appear to be children. We've also have had people come through who want to know how to chlorinate phenyl propenes...if you know what I mean. I always try to encourage some book knowledge before attempting any kind of wet chemistry. The last thing I want to do is discourage chemical curiosity. However, at some stages I believe that curiosity is best put to use working problems or studying chemistry. Yeah I think it's stupid that people don't have legal access many quite benign reagents. Much of that is the product of political fear mongering and public ignorance.

Spoken like a true amateur. Chemistry has advanced far beyond that at this point in time. If an amateur experimentalist were to discover something, he would most likely never know about it without a lab full of characterization equipment. Amateurs simply don't have access to the reagents, knowledge, equipment, or safety gear necessary to handle professional grade research projects. Ask the other trained chemists in this thread, you'll get similar results back from them. Without a little chemophobia, you're are likely to die or get fired quickly in a professional laboratory setting. There is nothing wrong with a little amateur chemistry playing but it will likely be nothing more than a semi-dangerous hobby.

Amen reverend. Stole the words from my mouth. Ethanol subsidies represent bad science, bad food policy, bad environmental policy, bad fiscal policy, and are the result IMHO of an ignorant legislature coupled with heavy corn lobby efforts.