As stated before it is standard procedure in histology labs.
I've done it countless times.
Normally I would put some anhydrous CuSO4 and pour ethanol on top of it.
Next day if I see that all CuSO4 is deep blue that means that all of it got hydrated, so I do second go to make sure that 12-24h later
there is some white/greenish CuSO4 left. That means that there was not enough water to hydrate it all therefore there is no more water in
ethanol solution.
It is really easy and reliable.
One portion of CuSO4 will last you forever to dehydrate ethanol or (nearly) anything else.
Just bake it to dehydrate it and its ready for another batch.
![[*]](images/xpblue/default_icon.gif){kind=icon}
