We have quite a lot of upvoted posts — 77 to be exact — using a website called ChemiDay as their reference material. However, from the looks of it, the website doesn't appear to be a reliable reference.

Suppose I have a question: "What are the products of the reaction between fluorine and ammonia?" Now, this is the related ChemiDay reaction. The entire webpage only: states the reaction and gives a very short description:

Ammonia react with fluorine

$$\ce{2NH3 + 6F2 → 6HF + 2NF3}$$

Ammonia react with fluorine to produce hydrogen fluoride and nitrogen(III) fluoride. The reaction takes place at the low temperature.

Most of the reactions in their database of ~17000 reactions (claimed) are like the one I linked to above. The question is: would we want the answer to this question be backed up by such a ChemiDay reference?

I instead would expect the answer to be backed by some reputed inorganic chemistry book (similar to March for organic), or at least a research paper - explaining the detailed experimental steps. For the above question, this research paper is apt. It clearly highlights major and minor products, and the different reactions at different yields of reactants.

I know we can't expect every answerer to be able to cite research papers or access good books, but does that mean we should sacrifice factual details and correctness with easy-to-lookup and (probably) wrong references?

So, should we officially disallow ChemiDay as a reference source (and leave a comment on such posts)? Or is there some other action we would want to take on such citations (for the past posts and for the future posts)?

  • 2
    $\begingroup$ Wikipedia has a “better citation needed” for this kind of thing, IIRC. $\endgroup$ Commented Jun 7, 2018 at 11:47
  • 13
    $\begingroup$ @orthocresol Definitely $^\text{[citation needed]}$; not sure about $^\text{[better citation needed]}$. $\endgroup$
    – hBy2Py
    Commented Jun 7, 2018 at 13:58
  • 5
    $\begingroup$ @hBy2Py apparently, it’s “better source needed”, which makes a bit more sense: en.wikipedia.org/wiki/Template:Better_source $\endgroup$ Commented Jun 11, 2018 at 8:25

2 Answers 2


No, it should not be considered a reliable source.

From a quick once-over, it appears to be trying to be, among other things, something of an "encyclopedia of reactions."

A true encyclopedia always cites its sources. As you note, citations therein are ... scarce.

So no, as it is, it's no good.


As you have noticed for some weeks that I am editing my old answers which has Chemiday as source (yes, my past-self is guilty of using Chemiday, please don't banish me :( ). I had around 15 such answers (I deleted 2-3 answers which was entirely Chemiday-crap and for the other answers, I edited and replaced the sources). By doing that, the answers became short and concise which looks good (before that it was more-or-less info-dumping).

Right now, there are two posts containing the word "Chemiday" both of which are questions.

  • 1
    $\begingroup$ Thanks Nilay! Now, 5 years later, I wouldn't probably bother with Chemiday references as long as the answer itself is correct. But I'm glad you took the time out to handle this 🙂 $\endgroup$ Commented Mar 7, 2023 at 13:30

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .