Examples:
- Chemical reactions (acids) with glycerol and possible small amounts of formaldehyde
- Mercury thiocyanate synthesis
- Homemade mineral water, or dangerous reaction?
- Will group 2 chlorides dissolve in water in water or react to produce distinct products? How does this differ by the type of salt?
These are the recent ones. There are many more but I am lazy to search them and its late at night. You get the point. Such questions discuss about synthesizing/mixing and dangerous and toxic chemicals. OPs clearly don't know what they are doing (or know ?) and something happens (which they don't know) and they ask questions which has this format: "I added X and Y. It foamed up/gas is evolving/color changed. What happened?". Like seriously, they are mixing potentially dangerous chemicals which are either toxic or oxidizers or carcinogenic which will straight up harm (or kill) you if you are not careful.
I comment on such question with bold letters: Don't do that. Don't mix chemicals if you don't know what will happen. OPs do not reply and either they don't care or are one-timers. So, the question is how to deal with such questions? Is just commenting sufficient enough?
The question get closed eventually but the current closing reason is "The question needs details or clarity(question unclear)/need more focus(too broad). Should there be a customs close reason for such questions?