Question

Prachi took 50 mL of water in two beakers at room temperature and added sodium chloride to one beaker while sugar to the other, till no more solute would dissolve. Then she heated the contents of the beakers and added more solutes in them.
(a) Will the amount of salt and sugar that can be dissolved in water at given temperature same ?
(b) What will you expect to happen if she cools the contents of the beakers ? Justify your answer.

Answer 1

(a) No, they will be different. Actually sodium chloride (salt) is a crystalline solid while sugar is a molecular solid. They dissolve to different extent. Sodium chloride is more soluble in water compared to sugar at a given temperature. (b) Upon cooling, solid solute will slowly start separating from the solution. In general, the solubility of a solid in a liquid increases with the rise in temperature and decreases as the temperature is lowered.