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I have seen many great physics questions in here, regarding material properties, atomic physics, physical chemistry and solid state physics. Case you don't as them on physics stack exchange. – Bernardo Kyotoku Dec 4 '10 at 9:07

Members of ACS or other professional organizations need to get the news about this SE! SE is very diverse, but these are great sources of specialists. – xenomancer Mar 17 '11 at 15:56

@Bernardo: There's a great deal of overlap between chemistry and other scientific disciplines, including physics, biology, and mathematics. – Bob Murphy Apr 7 '11 at 23:44

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This proposal is now in the Commitment phase — example questions are locked!

80 Example Questions (10 closed)

active oldest votes

up vote 2 down vote

added by Bob Murphy Nov 30 '10 at 17:38

up vote 2 down vote

added by avakar Dec 16 '10 at 16:21

Excellent chemistry question. What's your other electrode made of? The electrolyte solution has become saturated with whatever-it-is sulfate, and as you keep pumping electricity through, you keep putting more whatever-it-is sulfate into the electrolyte, so it's precipitating out. – Bob Murphy Dec 19 '10 at 3:07

@Bob, thanks :) Both electrodes are copper; the sulfuric acid is being turned to copper sulfate. Beyond the fact that the amount of copper sulfate increases, is it possible that with sulfuric acid vanishing, the pH of the solution increases, decreasing the solubility of the copper sulfate? – avakar Dec 19 '10 at 22:16

Hmm. That sounds fishy. You're basically schlepping copper from one copper electrode to the other; there should be no pH change. However, you could also simply be dissolving your copper electrodes by a redox reaction which would generate hydrogen gas from the protons dissociated from the sulfuric acid as a by-product, and you'd get copper sulfate precipitate. Do you see bubbles? (Don't light any matches... :-) – Bob Murphy Dec 23 '10 at 6:09

up vote 2 down vote

added by annemphillip Jan 23 '11 at 22:59

An excellent question. I'm not sure people know the answer to this yet. – AcidFlask Feb 21 '11 at 5:37

Actually, it's pretty simple. Gases are miscible, so as each nitrogen bubble passes through the water, some of the oxygen dissolved in the water migrates into the bubble. As you keep bubbling more nitrogen through, you remove more and more of the dissolved oxygen. It's really the same as if you mixed up salt and sand, and ran water through the mixture: you'd "de-salt" the sand. – Bob Murphy Apr 7 '11 at 23:54

up vote 2 down vote

added by Radu Feb 6 '11 at 16:10

Wow, what a great organic chemistry question, with quantum mechanical implications! – Bob Murphy Apr 7 '11 at 23:58

up vote 2 down vote

added by QH7 Feb 12 '11 at 13:02

Great question, and the answer differs based on the type of bond. For instance, chlorine is sigma-withdrawing but pi-donating, and the reasons for the difference are quite interesting. – Bob Murphy Feb 13 '11 at 22:07

up vote 2 down vote

added by robin, edited by WikiSpeedia hang-around Feb 22 '11 at 6:39

	It's a simple measurement to do. I'm sure Google know this as well. – M'vy Mar 1 '11 at 17:16
	An on-topic question would be "What is pH?" – tryaria Mar 1 '11 at 23:23
	I know what is pH but I dont know the pH value for coke and pepsi. – robin Mar 2 '11 at 4:06
	Off-topic. To expand on what googletorp said elsewhere, I don't think we want this site to become an encyclopedia of physical constants people could easily find using a search engine. – Bob Murphy Mar 30 '11 at 4:14

up vote 2 down vote

added by robin, edited by WikiSpeedia hang-around Feb 22 '11 at 6:38

How about HSO4-? :P – Radu Feb 19 '11 at 20:08

up vote 1 down vote

added by dthorpe, edited by WikiSpeedia hang-around Dec 20 '10 at 16:17

Interesting question with a very long answer. – Bob Murphy Dec 1 '10 at 6:02

Such questions would have many variable depending on what one has at one's place. Many reasons might be practical problems not pertaining to chemistry as such. – QH7 Feb 12 '11 at 12:41

up vote 1 down vote

added by WTP Aug 14 '10 at 17:37

I don't think that this question is specific enough. – Radu Nov 4 '10 at 13:33

Actually, it's a very serious question in physical organic chemistry. P.D. Bartlett did some quite striking work around this during the 1930s at Harvard, using substituted benzoic acids, that's still widely cited, and forms the basis for modern structure-activity relationship theory which is fundamental to areas like pharmaceutical design. However, the answer wouldn't be short. :-) – Bob Murphy Nov 30 '10 at 7:01

up vote 1 down vote

added by Bob Murphy Nov 30 '10 at 17:40

up vote 1 down vote

added by CrazyJugglerDrummer, edited by WikiSpeedia hang-around Dec 20 '10 at 16:09

closed as off topic by iansinke, Nick T, Cody Gray, Radu, M'vy Mar 1 '11 at 17:12

This question does not relate to the topic of the proposal.
It was closed as part of an automated migration of off-topic to close votes on September 29, 2011.

I'm waiting for Bernardo to claim this is a physics question. Actually, it kind of is... :-) But it certainly has implications for chemistry in fundamental ways. For instance, a given photochemical reaction requires photons with a particular minimum energy (frequency). If your light source is below that frequency, you can pump in as much power as you want and no reaction will occur. However, the wave nature of light is also important to chemists. – Bob Murphy Dec 13 '10 at 7:02

True that the wave and particle natures of light are important to chemists, but chemists don't need to study the 'why' they are the two, just be able to know that they are. As such, I wouldn't preclude a question that requires the understanding, but I think that asking directly about the duality of a photon is off-topic. – tryaria Mar 1 '11 at 23:17

@tryaria: Speaking as a chemist, I would have never gotten an adequate grade in quantum mechanics and been admitted to doctoral candidacy if I hadn't thoroughly mastered wave-particle duality. – Bob Murphy Mar 30 '11 at 4:28

up vote 1 down vote

added by CrazyJugglerDrummer Dec 4 '10 at 0:57

up vote 1 down vote

added by John Jan 11 '11 at 19:08

Really bad newbie question, but I think it's going to get asked anyway. – John Jan 11 '11 at 19:09

up vote 1 down vote

added by PleaseStand Jan 11 '11 at 22:47

This is badly worded. It would be better to say, "What use is Bohr's model in chemistry?", and the answer is, "None, and it never has been any use." The Bohr model is a "flat" atom, and is only useful for explaining emission spectra. Bohr knew it was a practical model with no theoretical underpinnings, and he ditched it as soon as quantum mechanics came on the scene twelve years later in 1925. Chemists have never used the Bohr model for anything; we've been aware of the three-dimensional nature of molecules since at least the mid-1800s. – Bob Murphy Jan 15 '11 at 22:38

Incidentally, in the US, the Bohr model is mostly propagated in elementary school, where the teachers have little or no science background, and the textbooks aren't written by scientists. It has the advantage that it's really simple to understand, and the disadvantage that everyone in the field - including Bohr when he first invented it - has always known it was a gross oversimplification. – Bob Murphy Jan 15 '11 at 22:43

up vote 1 down vote

added by PleaseStand Jan 11 '11 at 23:02

up vote 1 down vote

added by Nick T Feb 3 '11 at 3:21

up vote 1 down vote

added by QH7 Feb 12 '11 at 12:59

up vote 1 down vote

added by Radu Feb 17 '11 at 4:56

up vote 1 down vote

added by robin, edited by WikiSpeedia hang-around Feb 22 '11 at 6:38

	the broadest definition would be C(n)H2O(n), when you have the same amount of water and carbon in a molecule. Thus the carbo-hydrate name. – Cedric Mar 29 '11 at 23:16
	@Cedric: it is not the broadest definition. It would exclude sucrose (table sugar), C(12)H2O(11) (molecular formula C12H22O11). – WikiSpeedia hang-around Mar 30 '11 at 11:52

up vote 1 down vote

added by robin, edited by WikiSpeedia hang-around Feb 22 '11 at 6:38

	You mean pi bond? – AcidFlask Feb 21 '11 at 5:27
	Excellent question with a lot of interesting ramifications. – Bob Murphy Mar 30 '11 at 3:58
	thanks......... – robin Apr 1 '11 at 9:30

up vote 1 down vote

added by AcidFlask Feb 21 '11 at 5:44

up vote 1 down vote

added by AcidFlask Feb 21 '11 at 5:56

up vote 1 down vote

added by AcidFlask Feb 21 '11 at 6:01

I made the numbers up btw. – AcidFlask Feb 21 '11 at 6:01

up vote 1 down vote

added by robin, edited by WikiSpeedia hang-around Feb 22 '11 at 18:12

up vote 1 down vote

added by wdkrnls, edited by WikiSpeedia hang-around Mar 30 '11 at 11:55

up vote 0 down vote

added by KennyTM Jun 9 '10 at 15:33

closed as off topic by Vortico, Tobias Kienzler, googletorp, dthorpe, ssakl Aug 17 '10 at 17:49

This question does not relate to the topic of the proposal.
It was closed as part of an automated migration of off-topic to close votes on September 29, 2011.

or Acidity, etc. The main point is whether question that simply asks a property of a chemical is allowed. – KennyTM Jun 9 '10 at 15:36

We don't want to make an encyclopedia. – googletorp Jun 9 '10 at 22:13

A case for the CRC Handbook? – Anonymous Oct 23 '10 at 5:49

I don't think this is a good question since you can easily find it with google. A better question would be "How do I explain the boiling point of Compound X", assuming that compound X does not follow trends. – Radu Nov 4 '10 at 3:07

Boiling point is an handbook/search case, but estimation of untabulated data are often useful. My point of view is no simple data, but how to make derivative data are good questions. – shellholic Nov 22 '10 at 17:07

up vote 0 down vote

added by Louis Rhys, edited by WikiSpeedia hang-around Dec 20 '10 at 16:16

	Duplicate / generalization of the "why is gold yellow and copper red?" question. – dthorpe Aug 23 '10 at 17:15
	Could be improved by being more specific. For instance, there are a limited number of reasons organic chemicals can be colored. – Bob Murphy Dec 1 '10 at 6:03
	The answer here is the basis of analytical chemistry - although generally outside of the visible spectrum. – tryaria Mar 1 '11 at 23:21

up vote 0 down vote

added by David Hollman Aug 31 '10 at 13:39

	Or should this be moved to a new proposed site for computational chemistry? – David Hollman Aug 31 '10 at 13:40
	I think so. This isn't really about chemistry per se. – Bob Murphy Dec 1 '10 at 6:04

up vote 0 down vote

added by JFW Nov 11 '10 at 14:20

	uh... answer is useful to many varieties of fields, including chemistry. Maybe more math like. – Bernardo Kyotoku Dec 4 '10 at 8:42
	The chemistry definition of an empirical formula is "the simplest whole number ratio of atoms of each element present in a compound". So, for instance, the empirical formula for ethane is CH3, while the molecular formula is C2H6. How one finds them is quite another story, and can involve some pretty crazy lab techniques. – Bob Murphy Jan 5 '11 at 5:27

up vote 0 down vote

added by oneat, edited by Beska Dec 1 '10 at 22:31

closed as off topic by Bob Murphy, John, glenneroo, Fabian, Cody Gray Feb 8 '11 at 14:24

This question does not relate to the topic of the proposal.
It was closed as part of an automated migration of off-topic to close votes on September 29, 2011.

That mostly deals with biology, neurology, psychology, etc. I'm sure the chemoreceptors in our taste buds are very interesting, but they're only a small part of this question. – Bob Murphy Dec 13 '10 at 6:29