Stack Exchange
log in sign up chat discuss faq users badges

Area 51 » Science

definition commitment beta
141
followers

Chemistry

Launched Q&A site for scientists, academics, teachers and students

Announcements

3  
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
4  
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
3  
@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
show 1 more announcement
1
vote
1
answer

How does Area 51 determine which users were most active on the beta?

feb 19 '18 at 18:01 Mithical 2,299
12
votes
4
answers

Computational Chemistry, official location?

apr 17 '12 at 15:00 Community♦ 1
0
votes
0
answers

Please can a moderator delete my “unregistered user” commitment so I can register using my StackExchange account?

apr 13 '12 at 14:17 Community♦ 1
5
votes
2
answers

Will we need MathJax/any other formatting here? [closed]

apr 6 '12 at 1:21 Community♦ 1
5
votes
0
answers

Reputation for some committers is incorrect

mar 30 '12 at 7:34 Mad Scientist 381

show 2 more discussions
discuss this proposal

79 Example Questions (10 closed)

active newest votes
up vote 1 down vote
How is light both a particle and a wave? [closed]
added by Gordon Gustafson, edited by WikiSpeedia hang-around Dec 20 '10 at 16:09
link

closed as off topic by ian93, 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.

1  
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
What labs are easy to set up, engaging, and entertaining for my students?
added by Gordon Gustafson Dec 4 '10 at 0:57
link
up vote 1 down vote
What does it mean when a compound is "unstable"?
added by John Jan 11 '11 at 19:08
link
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
Why, to some extent, is Bohr's model of the atom sufficient for chemistry?
added by PleaseStand Jan 11 '11 at 22:47
link
1  
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
2  
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
Which compounds contain both an ionic and a covalent bond?
added by PleaseStand Jan 11 '11 at 23:02
link
up vote 1 down vote
How is the energy released in ATP hydrolysis by an enzyme transferred to the substrate to help create an ordinarily unfavorable bond?
added by Nick T Feb 3 '11 at 3:21
link
up vote 1 down vote
What's the main difference between a deoxyribonucleic acid and ribonucleic acid?
added by Qyuubi Feb 12 '11 at 12:59
link
up vote 1 down vote
Why does oxygen bind to heme in a bent conformation while CO binds linearly?
added by Radu Feb 17 '11 at 4:56
link
up vote 1 down vote
What is the chemical formula for carbohydrate?
added by Robin, edited by WikiSpeedia hang-around Feb 22 '11 at 6:38
link
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
What are PI bonds in chemistry?
added by Robin, edited by WikiSpeedia hang-around Feb 22 '11 at 6:38
link
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
When do I use enthalpy vs free energy to calculate the energy change?
added by AcidFlask Feb 21 '11 at 5:44
link
up vote 1 down vote
Is sp2 carbon more or less electronegative than sp3 carbon?
added by AcidFlask Feb 21 '11 at 5:56
link
up vote 1 down vote
The reaction CH3Br + CH3COOH --> CH4 + CH3COOBr has an enthalpy of reaction of -59 kcal/mol, but AMBER tells me it is +3 kcal/mol. Why?
added by AcidFlask Feb 21 '11 at 6:01
link
I made the numbers up btw. – AcidFlask Feb 21 '11 at 6:01
up vote 1 down vote
What is the chemical composition of blood?
added by Robin, edited by WikiSpeedia hang-around Feb 22 '11 at 18:12
link
up vote 1 down vote
What is a good resource for finding data on equilibrium constants for industrially common reactions?
added by wdkrnls, edited by WikiSpeedia hang-around Mar 30 '11 at 11:55
link
up vote 0 down vote
What is the [boiling point] of 22-Dihydroergocalciferol? [closed]
added by KennyTM Jun 9 '10 at 15:33
link

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.

1  
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
3  
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
3  
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
1  
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
Why do solid substances have different colours? What determines their colours?
added by Louis Rhys, edited by WikiSpeedia hang-around Dec 20 '10 at 16:16
link
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
How do I use an arbitrary basis set with Q-Chem 3.2?
added by David Hollman Aug 31 '10 at 13:39
link
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
What are empirical formulas and how does one find them?
added by JFW Nov 11 '10 at 14:20
link
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
How does our sense of taste operate? [closed]
added by oneat, edited by Beska Dec 1 '10 at 22:31
link

closed as off topic by Bob Murphy, John, glenneroo, Mad Scientist, 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.

1  
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
up vote 0 down vote
I've got some house plants. If I feed them twice as much chemicals, will they grow twice as fast? [closed]
added by Bob Murphy Dec 3 '10 at 6:16
link

closed as off topic by Yasir Arsanukaev, Mad Scientist, NewName, tryaria, biLOLogy Mar 29 '11 at 19:49

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.

Deliberately off-topic: really a botany question, and too vague even for that. Not to mention the bad grammar. :-) – Bob Murphy Dec 3 '10 at 6:18
up vote 0 down vote
Why is it so difficult to predict the spectrum of peptide fragmentation (given the amino acid sequence) in a mass spectrometer?
added by WikiSpeedia hang-around Dec 20 '10 at 16:38
link
(Spectrum: relative abundance of fragments as a function of mass-to-charge ratio.) – WikiSpeedia hang-around Dec 20 '10 at 16:39
Are questions about colliding molecules in the gas phase and the consequence thereof on-topic or off-topic? – WikiSpeedia hang-around Dec 20 '10 at 16:42
My doctoral research in physical organic chemistry involved colliding molecules in the gas phase and the consequences thereof, so I'd hope it's on-topic. :-) – Bob Murphy Jan 15 '11 at 22:54
up vote 0 down vote
How to synthesize silica nanoparticle?
added by Ravisankar S Jan 9 '11 at 13:14
link
up vote 0 down vote
How do anti oxidants added in polymers work?
added by Qyuubi Feb 12 '11 at 13:08
link
up vote 0 down vote
How do detox diets to rid the body of toxic chemicals work?
added by AcidFlask Feb 21 '11 at 5:40
link
up vote 0 down vote
What is the thymus gland?
added by Nuha Mar 11 '11 at 19:50
link
up vote 0 down vote
What is the acid base balance?
added by Nuha, edited by WikiSpeedia hang-around Mar 12 '11 at 21:40
link
up vote 0 down vote
What is the difference between stationary fluids and mobile fluids?
added by Nuha, edited by WikiSpeedia hang-around Mar 12 '11 at 21:40
link
up vote 0 down vote
What are equations of state and why are there so many?
added by xenomancer Mar 15 '11 at 17:29
link
Very good, on-topic question. They developed over time as measurements and theoretical understanding improved. It's kind of like "why do we need both Newtonian and Einsteinian mechanics". – Bob Murphy Mar 30 '11 at 4:10
up vote 0 down vote
Is it legal to privately synthesise [formula] (in [country])?
added by M'vy, edited by WikiSpeedia hang-around Apr 17 '11 at 18:19
link
up vote 0 down vote
What property of acids indicates the degree to which they dissolve? For example, hydrofluoric acid is a weak acid but is very corrosive.
added by Alex B Apr 20 '11 at 2:14
link
up vote -1 down vote
What's a photon? [closed]
added by googletorp Jun 9 '10 at 9:20
link

closed as off topic by KennyTM, Vortico, Tobias Kienzler, Beska, dthorpe Aug 13 '10 at 0:21

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.

Off-topic, photons are not explained with chemistry, the use or observation of photons in a chemical reaction would be on-topic. – googletorp Jun 9 '10 at 9:21
This would be more physics-related than chemistry. area51.stackexchange.com/proposals/1908/physics – Vortico Jun 10 '10 at 19:45
@Vortica Since it's a very fundamental question I'd prefer it on Popular Natural Science area51.stackexchange.com/proposals/4955/… – Tobias Kienzler Jun 11 '10 at 7:32
Definitely off-topic. However, the way photons promote electrons into higher-energy orbitals, resulting in photochemical reactions that wouldn't occur thermally, is quite interesting. – Bob Murphy Dec 1 '10 at 4:30
Actually, the chemist's definition of what a photon is is very relevant to chemistry - particularly to physical and analytical chemistry. I don't think this is a good example of an off-topic question. – tryaria Mar 1 '11 at 23:08
up vote -1 down vote
Why are all isotopes of technetium radioactive? [closed]
added by KennyTM, edited by WikiSpeedia hang-around Dec 20 '10 at 16:25
link

closed as off topic by googletorp, Tobias Kienzler, Vortico, ssakl, dthorpe Aug 13 '10 at 0:20

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.

1  
Radioactivity by itself is not a chemistry question. – googletorp Jun 9 '10 at 22:14
it's rather (nuclear) physics. And to date not entirely answerable – Tobias Kienzler Jun 10 '10 at 7:38
1  
I would argue that this can still be considered chemistry, since many people specifically design molecules with certain isotopes for various purposes in chemistry. Definitely a great "off-topic" example though – David Hollman Aug 31 '10 at 14:24
Despite the current votes (1 on:19 off) and my agreement with the general trend, I feel compelled to point out that Marie Curie won both the Physics and Chemistry Nobels for her work on radioactivity. – AcidFlask Feb 21 '11 at 5:36
1  
This is an important chemistry question when you get into fields outside of pure chemistry - for example geochemistry. One of the major areas of study in geochemistry is based on radioactive decay, so understanding which elements are radioactive, and why, can be considered chemistry. I don't think we should waste one of the five example questions to point out that radiation might be better investigated in physics. – tryaria Mar 1 '11 at 23:10
show 1 more improvement suggestion
up vote -1 down vote
How would one determine an equation that would calculate the color of a compound given elemental spectroscopy data?
added by Ned Nov 17 '10 at 4:16
link
physics question – Bernardo Kyotoku Dec 4 '10 at 8:28
To estimate color, you need a lot of chemical data beyond just elemental spectroscopy. For instance, with organic compounds, you need to know the compound's 3-D molecular structure, and pay particular attention to conjugated pi bonds. – Bob Murphy Dec 13 '10 at 6:48
Question needs some editing. @Bernardo Kyotoku this is actually an important physical and analytical chemistry question. For that matter, it has applications into organic and inorganic chemistry. Just because it deals with light doesn't make it pure physics. – tryaria Mar 1 '11 at 23:23
up vote -1 down vote
What does the AP chemistry test cover? [closed]
added by Gordon Gustafson Dec 4 '10 at 0:56
link

closed as off topic by Cody Gray, Qyuubi, Richard Terrett, ogerard, Mad Scientist Apr 16 '11 at 7:23

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.

3  
Everything. :-) – Bob Murphy Dec 13 '10 at 7:05
Seems a bit too obviously off topic. – tryaria Mar 1 '11 at 23:18
up vote -2 down vote
What are molecular formulas and how does one get them? [closed]
added by JFW Nov 11 '10 at 14:20
link

closed as off topic by UTChemistry, Bob Murphy, irrelephant, ian93, Borror0 Jan 16 '11 at 7:19

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.

3  
This is really two different questions. "What are molecular formulas" can be explained in a few minutes. "How does one get them" is very complex and people spend careers on that. – Bob Murphy Nov 30 '10 at 7:07
@Bob Murphy Just because the answer may be long winded doesn't mean that the question is bad. I agree that this should be two questions, but the second does have a standard answer. – tryaria Mar 1 '11 at 23:14
up vote -4 down vote
How is Fortran better than other programming languages for chemistry related calculus?
added by mvime, edited by WikiSpeedia hang-around Dec 20 '10 at 16:27
link
This would probably be a good topic for the proposed Computational Chemistry site – David Hollman Aug 31 '10 at 14:26
Thanks, David. I joined the proposal : ). It'd be great to have some place to post all the questions I can't get answers for in class. – mvime Sep 1 '10 at 21:43
up vote -6 down vote
Where can I download [chemistry book]?
added by Svante Sep 15 '10 at 13:14
link
Maybe try, free chemistry books, or free resources for learning chemistry. – Radu Nov 4 '10 at 3:12
up vote -12 down vote
How to know when you have good chemistry with your {boyfriend/girlfriend}? [closed]
added by Binoj Antony Jun 17 '10 at 10:08
link

closed as off topic by Douglas S. Stones, Bless, ssakl, dthorpe, Tantalus Nov 16 '10 at 17:56

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.

1  
Intended as off topic. – Binoj Antony Jun 17 '10 at 10:09
1  
avoid silly off topic questions, add only those that are probably asked in the site – Louis Rhys Aug 23 '10 at 7:02
3  
this is a bit ridiculous.... – David Hollman Aug 31 '10 at 13:36
prev 1 2

This site has

Launched!

This Stack Exchange site's beta was successful, so it launched 5 years ago.

proposed by

googletorp ♦ 1
92.6k●40●242●447

10 years ago

viewed

13,044 times

latest activity

9 years ago

followers

users also following

16.3% Biology
12.1% Academia
11.3% Computational Sci...
11.3% Physics
13.5% only this proposal

followers active in

71.6% Stack Overflow
43.3% Super User
39.0% Mathematics
35.5% English Language...
35.5% Meta Stack Overflow
31.9% Meta Stack Exchange

recent followers

added May 8 '12 at 14:36
rcollyer
52.1k●16●180●363
added May 7 '12 at 6:26
Sam
2,881●4●29●58
added May 6 '12 at 6:50
Eric Fode
3,967●1●24●39
added May 5 '12 at 10:56
Douglas S. Stones
40.2k●17●174●362
added May 3 '12 at 1:18
anonymous
3,998●2●13●35
added May 2 '12 at 23:43
Jason Waldrop
2,273●3●15●54
added Apr 30 '12 at 13:15
Michael Feng
51●2
added Apr 29 '12 at 13:20
Ben
730●2●5●14
added Apr 29 '12 at 1:17
yibe
5,299●6●35●39
added Apr 28 '12 at 22:45
mgkrebbs
26.7k●5●142●273
added Apr 28 '12 at 12:38
noob
25.7k●27●163●368
added Apr 27 '12 at 22:29
user57287
51●1
added Apr 27 '12 at 3:36
user57207
51●1
added Apr 24 '12 at 12:52
EnergyNumbers
85.4k●21●331●784
added Apr 21 '12 at 8:46
Mats Granvik
8,947●3●47●110
added Apr 21 '12 at 4:14
Terry Bollinger
25k●6●86●162
added Apr 20 '12 at 20:13
Clemens
61.8k●5●159●362
added Apr 17 '12 at 12:47
Jorge
1,365●10●12
added Apr 16 '12 at 13:40
Manishearth
225k●83●789●1678
added Apr 16 '12 at 5:56
Bidella
3,177●4●20●33
added Apr 4 '12 at 3:11
sam
10.4k●28●93●146
added Mar 31 '12 at 0:18
user55510
51●1
added Mar 25 '12 at 19:29
matt_black
109k●43●354●728
added Mar 11 '12 at 18:24
Dillon Cower
2,599●16●18
added Mar 9 '12 at 19:58
Circeus
21k●48●108
added Mar 7 '12 at 14:46
Jez
1,418●11●21
added Feb 27 '12 at 18:50
user53444
51●1
added Feb 18 '12 at 5:25
Anil
2,342●2●19●47
added Feb 15 '12 at 22:23
Mononess
913●3●16
added Feb 12 '12 at 4:01
jonsca ♦ 2
77.7k●117●421●907
added Feb 11 '12 at 21:38
CHM
7,291●1●41●100
added Feb 7 '12 at 1:11
Kevin ♦ 2
150k●53●475●807
added Jan 31 '12 at 6:14
Dan
36.1k●26●175●395
added Dec 24 '11 at 3:15
pentavalentcarbon
7,467●5●42●79
added Dec 9 '11 at 14:19
rjstelling
48.9k●46●243●466
added Oct 18 '11 at 3:00
Canageek
27.1k●13●124●293
added Oct 17 '11 at 0:38
Daniel ♦ 1
73.2k●82●340●644
added Sep 30 '11 at 11:08
Nicolas Kaiser
3,880●6●33●97
added Sep 27 '11 at 13:27
PearsonArtPhoto ♦ 1
272k●121●1018●1867
added Sep 19 '11 at 17:45
Dan the Man
27.1k●36●173●400
feed icon proposal feed
faq | blog | legal | privacy policy | contact us | feedback always welcome
site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa; see the licensing help page for more information.
rev 2021.3.15.578