How to separate alcohol and water

Alcohol and water mix instantly! But how can you split them in a flash?

Safe­ty pre­cau­tions

Warn­ing! Only un­der adult su­per­vi­sion.


  • glass bot­tle with cap;
  • wa­ter;
  • iso­propyl al­co­hol;
  • sodi­um chlo­ride (salt);
  • food col­or­ing.

Step-by-step in­struc­tions

Mix some iso­propyl al­co­hol and wa­ter in a bot­tle to cre­ate a ho­mo­ge­neous liq­uid. Add salt and food col­or­ing and shake the mix­ture well – the liq­uid read­i­ly sep­a­rates into al­co­hol and wa­ter, and the wa­ter is tint­ed more vivid­ly than the al­co­hol.

Process de­scrip­tion

Al­co­hol and wa­ter will mix with each oth­er in any ra­tio. Sodi­um chlo­ride dis­solves well in wa­ter, but poor­ly in al­co­hol. When salt is added to the pre­pared so­lu­tion, it at­tracts wa­ter mol­e­cules to it­self, “dis­tract­ing” them from the al­co­hol mol­e­cules. As a re­sult, when the mix­ture is shak­en, the al­co­hol mol­e­cules sep­a­rate from the wa­ter to form a sec­ond lay­er of liq­uid. Since wa­ter is more dense than al­co­hol, the wa­ter winds up at the bot­tom. The wa­ter is also tint­ed more vivid­ly be­cause food col­or­ing, like salt, dis­solves bet­ter in wa­ter.

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