Recently, I've seen a trend of $\mathcal{\color{red}{SCARY}}$ questions back on chem. They're mainly about this:

Get the picture? No? OK, I'll be more straight-forward 1:

How to dissolve fifteen elves and seventeen trolls ASAP?
How much does it take to dissolve an angry bird with hydrochloric acid?

Are these questions entertaining enough not to touch them? Maybe the scariness isn't a problem but the interesting thing is the asker usually has made no research and asks for 4-hour-long calculations. We won't be able to answer them precisely, but they aren't clearly outlined in the help center as off-topic.

Now, theoretically, how should we deal with these questions? Do we need to modify our FAQ? Leave them alone? Downvote and move on? Everyone share your valuable ideas please.

As a response for comments, I officially add the link to those questions for real evidence, so folks who don't have a clear image about what I'm talking about can participate too: 2

How long would it take to dissolve someone using fluoroantimonic acid?

Is there any chemical mixture which could liquidize a person in a couple minutes?

The first one basically claims I know it's hard, but imagine this and calculate it. We never treat homework questions like that with answers. We typically close them as Off-topic.

The second question is just a curious person wondering if what happens in movies can happen in real life. 3 This question is too broad/primarily opinion-based. Chemists are gonna go acid-hunting to find the answer; the answer isn't going to need expertise, it would need guesses and some calculations at best.

So what I'm basically saying is this topic doesn't seem to attract quality questions. If it doesn't, then it's a leech. We should burn it with fire! (AKA ban it or something)

1: No, no links! I hate the meta effect.
2: With special thanks to Martin for locking those posts so there won't be any meta effect.
3: And I'm yet to see something in a movie that actually happens in real life $\ldots$

  • $\begingroup$ Hmm, funny thing it looks like homework stuff, only you know... :D $\endgroup$
    – Mithoron
    Commented Aug 5, 2015 at 21:35
  • $\begingroup$ linkback to some related meta: meta.chemistry.stackexchange.com/q/19/4945 $\endgroup$ Commented Aug 6, 2015 at 9:09
  • $\begingroup$ See meta.chemistry.stackexchange.com/questions/235/… $\endgroup$
    – Ben Norris
    Commented Aug 6, 2015 at 11:09
  • $\begingroup$ @Aify we always comment and ask for research if research is expected. 70% of the time the asker responds with their research in comment, and we add them to the question. The other 30% either don't respond or say plzzz halp i wants answers! and then we close the question. I stated that they don't do research because they even generally state that in their question. Just saying I'm not a chemist so I didn't do calculations is not a good excuse. $\endgroup$
    – M.A.R.
    Commented Aug 6, 2015 at 16:56
  • 1
    $\begingroup$ As a side note, if we count the Spallation Neutron Source as a neutron gun, the answer to the title-question is probably "One." $\endgroup$
    – chipbuster
    Commented Aug 6, 2015 at 17:45
  • $\begingroup$ Answer is written. (previous comments removed) Also, related because of your recent edit containing the "quality questions" statement. (Please read) blog.stackexchange.com/2011/06/optimizing-for-pearls-not-sand $\endgroup$
    – Aify
    Commented Aug 6, 2015 at 17:49
  • $\begingroup$ @Aify I've read that like, 10 times. That's not really relevant IMO (it's usually used as a question vs. answer slogan) . Even if we use the motto, it's proving my point: Don't allow asking questions that produce a lot of sand and not considerable pearl. You might wanna come to Chemistry Chat and discuss it with us though. Ideas always welcome! $\endgroup$
    – M.A.R.
    Commented Aug 6, 2015 at 17:53
  • $\begingroup$ My question about vampires in Mathematics SE was closed (eventually), but my question there about exploding water is still open. So perhaps case-by-case is best? $\endgroup$
    – uhoh
    Commented May 21, 2019 at 3:39
  • 1
    $\begingroup$ @Uhoh it varies even more by site. Math.SE is more lax with moderation, or so I've heard. Either way, two examples aren't enough to draw any meaningful conclusion. $\endgroup$
    – M.A.R.
    Commented May 21, 2019 at 5:42
  • $\begingroup$ @M.A.R.ಠ_ಠ I think it's more that the Math.SE community is pretty well-behaved. btw it seems I'd forgotten to add the humor flag to my previous comment ;-) $\endgroup$
    – uhoh
    Commented May 21, 2019 at 5:53

7 Answers 7


TL;DR: We should downvote and flag/close as off-topic. We do not need to add rules to cover these questions. The existing ones work fine.

These "questions" are off topic because they are not asking about chemistry. They are asking about using a specific compound for some bizarre purpose. We do not need to add to our off-topic list unless this behavior becomes prolific and obnoxious. Statements in our What topics can I ask about here? and What types of questions should I avoid asking? pages already cover questions like these:

From the on-topic page:

Questions may be of any level, but should be of the following types:

  • Questions asking for explanation of a chemistry concept
  • Questions relating to observed chemical phenomena
  • Questions about experimental techniques and technology
  • Questions about nomenclature, standards, et cetera pertaining to chemistry.

These questions cannot easily fit into any of these categories. They are not asking for explanations of chemical concepts, phenomena, experiments, etc.

From our don't ask page (emphasis mine):

  • You should only ask practical, answerable questions based on actual problems that you face.
  • Constructive subjective questions... are more than just mindless social fun.

In other words, just because the question is about using a chemical substance for a specific application that is more often found on a shelf in a lab than a shelf in the supermarket does not make the question about chemistry.

See this meta post: Should "Chemical Request" questions be on topic here?

Here is an example that we would feel is more clear cut, but is right along the lines of I'm trapped in the chemistry lab and the zombies are about to break down the door. What should I use against them first?

Off-topic question, belongs on Gardening & Landscaping

How much bleach do I need to kill weeds?

I know that I can use bleach (which decomposes into nontoxic stuff) to kill weeds along my fence line. What concentration should I buy? What is the best way to dispense it? Is there any downside to using bleach over more expensive weedkillers (which may contain toxic chemicals)?

On-topic version (probably, though maybe Earth Science or Biology)

What does bleach do to soil?

I have been using bleach as a weedkiller for a few weeks now, and it is awesome. I have been wondering how bleach changes the soil chemistry to make it less hospitable for plant growth.

These questions are not quite boat programming questions, but they are off-topic in the way that boat programming questions are off-topic. These questions are more about boats (applications, bizarre or otherwise) than programming (or chemistry).

  • 2
    $\begingroup$ Please note the wording of the "on-topic" page; it says "Should be", not "Must be", which reads to me as "If it's not one of these, it's likely to be off topic, but not guaranteed to be". $\endgroup$
    – Aify
    Commented Aug 6, 2015 at 15:36
  • 1
    $\begingroup$ An excellent point. I'd like to point out, though, that if we were to try to retroactively apply it, we'd probably end up expunging at least 10% of the questions on this site. Not that we'd have to, but it seems like, historically, a lot of these types of questions haven't been closed for being off-topic. $\endgroup$
    – chipbuster
    Commented Aug 6, 2015 at 17:55
  • $\begingroup$ To the future readers, I accepted this answer as it seems to reflect the community consensus more. If you're going to ask questions like these, please note that we'll deal with them in a case-by-case basis; and unless your wording clearly makes them a question that fits the chem.SE model, they'll be closed as off-topic. $\endgroup$
    – M.A.R.
    Commented Aug 7, 2015 at 10:29

I'm going to come at this from a slightly different perspective, by quoting from David Sirlin's Playing To Win. In the chapter "What Should Be Banned?" Sirlin makes the case that

A ban must be enforceable, discrete, and warranted. (emphasis mine)

We certainly have the enforceable part: if it violates the rule, we close the question and downvote it to oblivion. Simple.

We also have the warranted, though that one is a little harder to justify so cleanly. Certainly if the community decides that these questions are a waste of time, then that should be enough of a reason.

But discrete...I'm not so sure about that one. (For the record, Sirlin seems to use "discrete" to mean "well-defined") For example, I could ask the question of why it takes so long for salicylic acid to dissolve a wart. The chemistry involved would be pretty similar to the question of "how fast can ______ dissolve a human corpse", but I'd be hesitant to ban the question about salicylic acid for being a scary question.

Similarly, a question on the kinetics of inhibition of acetylcholinesterase by phosgene oxime could be on-topic, though that could easily be turned around into "How long would it take a human to be killed by phosgene gas?"

If we're going to make a rule about these sorts of questions, we need some sort of explicit rule that can be applied these kinds of questions and only these kinds of questions.

If we can't come up with one, I think we're better off just downvoting or tutting disapprovingly and moving on, as opposed to trying to enforce a vague and nebulous rule.



I suppose that I'm the one to blame for all of this.

On Worldbuilding, I asked How can I liquefy my enemies?, which was one of our pseudo-open-ended questions. I was looking for some sort of process that would take a human being a reduce him or her to a liquid-y state within sixty seconds, give or take. There, Aify answered first, suggesting the use of fluoroantimonic acid. The rationale for it was explained, and its candidacy seemed to be an a firm base. The only thing in question was whether or not it could meet the sixty-second requirement. Therefore, Aify asked How long would it take to dissolve someone using fluoroantimonic acid? on Chemistry. Later on, DoubleDouble mentioned that s/he had brought up a more general question, Is there any chemical/mixture which could liquidize a person in a couple minutes or less?.


The reason that these questions were asked on Chemistry was to provide a solid scientific basis for all acid-based attacks on humans, to be used in answers to the question on Worldbuilding. Nobody that paid much attention to the acid proposals knew how to do any relevant approximate calculations or find relevant data (which most likely doesn't exist) - at least, nobody who stepped forward. Therefore, it made some sense, I suppose, for somebody (two somebodies) to ask on Chemistry, where there was a good shot at the questions being answered. Some of us made a stab or two at it - comments mentioning possible ways to figure it out can be found in a chat room - but there were no successful attempts.


I find the questions somewhat interesting, but - and I apologize if I come down hard on them - I don't think they should have been asked on Chemistry. They ask for a calculation, and that fits the pattern of a homework question, however weird it may be. Yes, some questions are allowed on Chemistry, but there are many that violate the homework policy, and so are closed. These are questions asking for computations, not a particular concept. Boiling it down, I think they are off topic. Perhaps that's an extreme interpretation, but I stand by it.

In the future

On Worldbuilding, there has been a push over time to have more questions be backed up by pure, solid scientific principles - we use the phrase and tag to describe it. I have been on of the most vocal and active - if not the most vocal and active - proponents of this philosophy. A recent question that exemplifies this is Creating a realistic world(s) map - Solar systems (disclaimer: I answered it). Even though the tag was not on my question - nor even , an older version of the concept that became way too overused - I think there was some pressure to come up with answers that were as realistic as possible, which is our overall policy, unless otherwise specified.

So, in the future, should there be this kind of cross-site asking - or, to better describe it, the asking of supplementary science questions to support a Worldbuilding question or answer? I say no. There is, at the moment, an unfortunate divide between questions on Worldbuilding and questions on pure science sites (though a divide that I'm working to whittle down). Worldbuilding questions are asked differently - not necessarily in a jocular fashion, but not necessarily 100% focused on the process of the science, so much as the result in the situation at hand. Mixing via migration has happened, which far too often does not go well.

So this last section really applies more to Worldbuilding users. Perhaps we should reconsider our relationship with other sites. Let's not pretend that the question models are the same - they aren't. We need to realize that question tone differs across Stack Exchange, and we need to change the manner of asking supplementary questions likewise. I do disagree at Todd Minehardt's characterization of them as "childish" - naïve, perhaps, but not childish (said the child) - but I think that there is a difference in tone.

Apologies (especially to inɒzɘmɒЯ.A.M!) if I succumbed to the meta effect, but I needed to give some context here. Fortunately, posts are editable, and links are removable!

  • $\begingroup$ I do agree that I was naive in posting my question.. on several levels - I expected a quick "every chemist knows this because its interesting" answer, even if it lacked the exact times/calculations. I assumed the dangerous chemicals involved would be very difficult to get. I was mistaken, but left my question open when I normally would have deleted it. I thought it would be better to have the "dangerous question" hammered out here on meta, and then deleted that way if it was deemed unsuitable - I will have no hard feelings if that is the outcome, and plan on taking more care in the future. $\endgroup$ Commented Aug 6, 2015 at 22:46
  • $\begingroup$ I think what you need is to find a way to market Worldbuilding to more chemists $\endgroup$
    – KalleMP
    Commented Jun 21, 2017 at 20:29

I'm not a writer myself, but I like to play what-if with science. I imagine for many people on the chem / physics SE sites, that's part of the appeal of hanging out here.

Let's look at this from a constructive POV. Is there a way for chemistry.SE (and physics.SE, and others) to help fiction writers trying to get the science correct and plausible for their stories? (perhaps this should be a separate question on meta, if it hasn't already been asked).

Perhaps a "what-if" or "sci-fi" tag could give license to solicit speculation and hand-waving from well-informed chemists on hypothetical questions. (This came up in comments on Todd Minehardt's answer.) This proposed tag or tags wouldn't be a free pass; there would still be questions that don't fit the rules for that tag, and have to get improved or deleted.

Other guidelines about how to write a question, and how to show your attempts at research and what you've already thought of would be needed.

Maybe a link to a worldbuilding.SE question in the chem.SE question would be appropriate, as some people might want to write answers to more than just the chemistry part of the question, and see the whole picture of what was being talked about. The two questions that got asked here on chem.SE are not good questions on their own, without the background of the worldbuilding.SE question that sparked them.

Allowing more speculative and open-ended questions than the current guidelines allow would have to be an experiment. It would have to be re-visited at some point to see if the community is still happy with things, and that it hasn't flooded the site and diluted the quality of other questions.

  • 2
    $\begingroup$ Peter to make "what-if" questions fit the SE format one has to try hard, and very hard I mean. There is a Scientific imagination proposal at Area51 and it's close to the commitment phase. Until then, I think you should post a meta question instead and have the community's opinion on this. $\endgroup$
    – M.A.R.
    Commented Aug 9, 2015 at 4:54

Summary: Let the system deal with it using voting and flags.

According to this answer from Martins linked meta, "Questions about (for instance) why explosives explode and how toxins or illicit substances act on the body should be fine." While I agree that a 4 hour long calculation might be too much, and you're right that the elves and trolls don't fit, if the calculation were to be reduced via (some method) and it applied to the human body, it should be fine.

Because you can't prove that they haven't done research, you shouldn't just assume that they haven't. For example, I recently asked a question (How long would it take to dissolve someone using fluoroantimonic acid?) that doesn't show the research I've done on it beforehand (several hours). The question sure doesn't look like I did research, but you shouldn't assume that I didn't. Innocent until proven guilty - if you're going to say someone didn't do research, you need a way to prove it. It was pointed out to me that this site also uses the same research policy as StackOverflow - in the future, I'll make sure to put "proof" of the research completed. If you don't like the question, you can DV or flag.

Example of a similar but well received question: Is it actually possible to dispose of a body with hydrofluoric acid?

Actually, that above question is more broad than the one I've asked.

With regard to the edit: The first one basically claims I know it's hard, but imagine this and calculate it. We never treat homework questions like that with answers. We typically close them as Off-topic.

That's not what it's saying at all. Note that while the question explicitly says that it is a hard calculation, it explains the reason why the calculation is hard, and provides a separate calculation which should be much simpler - the only thing missing is the material for which to substitute in. It's not saying "it's hard but do it anyways", it's saying "It's hard, so lets do this instead." It's just that "this" hasn't been identified. The lack of real world research into the acid in question makes it extremely hard to get any data on it, regardless of the time spent doing research. Even in the comments, it's been stated that even if the calculation wasn't actually done, OP was willing to settle for guidance as to how OP could do the calculation - not a do this for me homework question at all.

  • $\begingroup$ That's not what it's saying at all. Note that while the question explicitly says that it is a hard calculation, it explains the reason why the calculation is hard, and provides a separate calculation which should be much simpler - Don't follow you there. It's still asking us to calculate without any effort on their behalf. $\endgroup$
    – M.A.R.
    Commented Aug 6, 2015 at 17:39
  • $\begingroup$ @inɒzɘmɒЯ.A.M OP was willing to settle for guidance as to how OP could do the calculation as stated in this answer, and the comments for the linked question. Also, note the example linked relating to hydroflouric acid. With a bit of rephrasing, the flouroantimonic acid could attract answers even more detailed than the ones in linked example. Given the lack of current data on flouroantimonic acid, I would think that calculations of any type would be a great addition to the value of the site. So far, all i've found on the acid is "it's too dangerous to work with, so there's no data." $\endgroup$
    – Aify
    Commented Aug 6, 2015 at 17:46
  • $\begingroup$ That I'm afraid doesn't work. The homework questions used to get answered with hints, but we realized two things: || 1) Answering them will not increase the quality of the question. If the OP gets answer with no effort, we open ways for rep-farmers and HW dumps. 2) What is a hint? That question is really hard to answer; there are lots of gray areas. || Thus, the homework question hints gradually disappeared. Furthermore, that info shouldn't be in the comments, but in the question itself. The question should be standalone, and I needn't go through a dozen comments to see that. (it's locked tho) $\endgroup$
    – M.A.R.
    Commented Aug 6, 2015 at 17:49
  • $\begingroup$ @inɒzɘmɒЯ.A.M I would have edited that information into the question but it got locked. Also, where is the grey area in the question? Also, please define the term "homework question" - I'm unfamiliar with what it's supposed to mean on this site, and the only reference I can find is one to how it's defined on SO. Also, read the link I've put in the comment under main question. Optimize for answers, not questions. Perhaps what you say "doesn't work" applies to most questions, but clearly not all. $\endgroup$
    – Aify
    Commented Aug 6, 2015 at 17:52
  • 1
    $\begingroup$ please see our homework policy for that matter. $\endgroup$
    – M.A.R.
    Commented Aug 6, 2015 at 17:55
  • 1
    $\begingroup$ "Innocent until proven guilty": this makes no sense. If you've done research, you should be expected to show what you already tried. This is like programming questions on stackoverflow. The first specific thing that's mentioned on stackoverflow.com/help/how-to-ask is to include your research, even relevant stuff you found that wasn't actually helpful, so answerers will know what's already been considered, and so on. Asking people to assume your 5-line question is the result of a ton of research is crazy, because most questions from most users aren't. $\endgroup$ Commented Aug 8, 2015 at 10:24

Are these questions entertaining enough not to touch them?

I find them somewhat childish, and don't think they bring much value to the site. Solubility calculations pertaining to hydroxyapatite, or how fluoride in toothpaste works, or any number of other human body-related questions are more interesting and higher-value to me.

Now, theoretically, how should we deal with these questions?

I don't mind seeing them closed or deleted, if possible. I don't think that digital chaff like that needs to be preserved.

Do we need to modify our FAQ?

Probably, but maybe the down-vote/close flag system will work. Remains to be seen(?)

Leave them alone? Downvote and move on?

Leaving them alone creates a digital magnet for others who want to chime-in on a subject that (to me) provides little to no value to the site. I wouldn't mind seeing them down-voted and closed or removed, if the last option is within the rules of SE in general and chem.SE in particular.

  • $\begingroup$ Do you think there's any scope for science-fiction writers asking somewhat broad or open-ended questions on chem.SE? i.e. Would you be ok with more detailed questions from people trying to work out how the science behind their idea would work? Or do you think any chemistry in support of science-fiction always belong on worldbuilding.SE, and people with detailed chemistry knowledge interested in questions like that should read that site? $\endgroup$ Commented Aug 8, 2015 at 10:33
  • 1
    $\begingroup$ I love reading well-researched fiction (science and other varieties): I'm all for writers getting the information they need, and understand that it's fundamental research in your/their field. I suppose my issue with the posts we're discussing here is that they tend to be high-traffic, open-ended affairs that don't conform to the existing guidelines/rules for the site. I would be supportive of, for example, the creation of a tag such as "What-If" or "Sci-Fi" or something to indicate that these questions are to be treated differently that the usual flow here. $\endgroup$ Commented Aug 8, 2015 at 14:55
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    $\begingroup$ I turned this idea into an answer. I think it would be cool to have sci-fi questions on the science sites, but I usually only visit when a neat one pops up in "hot network questions". Mostly I hang out on stackoverflow and optimize x86 asm code. $\endgroup$ Commented Aug 9, 2015 at 3:41

Why is there such a fear of chaff, bad questions, bad answers, lack of research on SE from some seasoned members.

New members just blunder along so they can be excused for their opinions.

What I cannot figure out is why it gets under peoples skin that there is some bad data in amongst the good. SE operates on a search engine or insomniac reader data retrieval system. There is no occasion for anyone to stumble across bad stuff unless they are interested in it.

Why should anyone care if a bad question, like Can baking soda be extracted from baking powder? (I guess it would be hard with no research to back this up) was badly answered and down voted nearly to oblivion, remains in the database?

  • If a question can be answered leave it alone.
  • If you want to answer a question then go for it.
  • If the question bothers you the fix it or down vote it.

The prime directive of SE is to preserve knowledge, why should we mere mortals nitpick about some chaff in the SE database that an AI will have to ignore one day because it does not make sense. Only OCD people actually perceive the bad data, it causes no other harm.

  • 1
    $\begingroup$ Bad questions clutter the front page if they are left open. They also make the site look less professional and more like yahoo answers (which is not what we want). $\endgroup$
    – bon
    Commented Jun 22, 2017 at 14:29
  • $\begingroup$ @bon The average visitor does not browse the front page. They find a Q(&A) via a search engine or are a contributor and then can pick their won page to visit. Catering to a mythical LCD is the way to make the OPs not return (with a more interesting question) and make the contributors tired of having interesting questions close before they have a chance to shine. It is not a beauty contest folks. $\endgroup$
    – KalleMP
    Commented Jun 25, 2017 at 17:04
  • $\begingroup$ The average answerer does browse the front page. If you want people to keep answering you need to keep the front page full of interesting questions, not bad ones. $\endgroup$
    – bon
    Commented Jun 25, 2017 at 20:27

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