This question (Is there a chemical that when added to water makes the water flash evaporate?) was posted 2 days ago, closed yesterday as being too broad and reopened today (14th Sep 2016 at 17:45Z, timeline). The question has never been edited so its contents are the same throughout.
I wonder why people voted to reopen it and why that vote subsequently went through. The question asks whether there is a chemical that can be added to water so that it will instantly flash evaporate. In my opinion, there are hundreds.
- dropping sulphuric acid into water will make part of it evaporate quickly.
- pouring liquefied salts into water will transfer large amounts of heat; some will cause explosive evaporation.
- Loong mentioned an enriched uranium salt that will induce a chain reaction in water.
- the answer it has is an azeotrope idea.
- I’m pretty sure that some tert-butyllithium will do the trick as well.
There is no constraint either visibly in the question or otherwise that would limit this question to a smaller number of answers. As such, I think it is far too broad and should have remained closed. I am very interested which arguments the reopen voters applied to reopen the question?
Note: Of course I am biased. I am one of the five who closed it in the first place.