>>13459639Are you familiar with thermodynamics?
You can just search a thermodynamic calculator (they exist) and input some random reaction you can think of like a double displacement or something. It should tell you the value for DeltaG. If it’s positive then it would be an endothermic reaction
For something that may last long, take your endothermic reaction and try to calculate a rate constant for it? If it’s barely above 1 then I would assume it wouldn’t react very fast
Sorry if this is a complicated answer I just honestly don’t know any off the top of my head
