Question #d1431

2 Answers
Mar 8, 2017

Find a solvent in which salt is insoluble, and in which sugar is soluble...........


And it is a fact that sodium chloride is almost completely insoluble in ethyl alcohol, whereas sugar has some (little) solubility.

Mar 9, 2017

Salt and sugar can be separated mechanically or chemically.


Chemically - Alcohol (Ethanol) can be used to separate sugar and salt by:

  1. Place Ethanol into the mixture. There must be enough ethanol to
    dissolve the sugar.
  2. Stir the mixture until the sugar is dissolved
  3. Run the salt/ethanol through a fine strainer Table Sugar (Sucrose)

Ethanol, an alcohol, dissolves sugar due to the hydrogen bond being easily broken by the ethanol. Salt is not dissolved by the ethanol because the dielectric constant is low (lower than water which dissolves salt).

Mechanically - You can also separate the two using a fine strainer although this is more difficult. One would need a filter size between 100 microns (Salt) and 500 microns (Sugar).