What is this separation in rubbing alcohol and salt?


I was cleaning my one hitter pipe in a ziplock bag with rubbing alcohol (I guess it’s called isopropyl) and salt and after a little bit of it sitting while I brushed my teeth, the liquid divided like oil on water. What could cause that separation/density/property change of the liquid?

It was salt, isopropyl, ash and tar from cannabis. Was something in the rubbing alcohol split from the water that’s in rubbing alcohol?

IMGUR pics: https://imgur.com/a/K7dKfbg

In: 2

Normally water and alcohol can mix in any proportions.

Salt dissolves in water but not in alcohol. Salt-saturated water doesn’t mix with alcohol that well because salt ions stick to water particles. Salt water is heavier so it settles to the bottom.

It looks like proportions are wrong, rubbing alcohol should be 70-30 alcohol to water, this is more like 50-50.

This effect can be used to purify solvents, for example adding salt to nail varnish remover could produce pure acetone.