State whether the following statements are True or False. Also, correct the False statements.
Salt can be separated from a salt solution by evaporation or distillation.
True. Salt can be separated from a salt solution by evaporation or distillation.
Distillation can be used for separation of two liquids even when these have the same boiling point.
False. Distillation cannot be used for the separation of two liquids if they have the same boiling point. Correction: Distillation can be used for the separation of two liquids only if they have different boiling points.
In paper chromatography, the solvent level should be above the sample spot at the beginning of the experiment.
False. In paper chromatography, the solvent level should be below the sample spot at the beginning of the experiment.
Evaporation and crystallization are the same processes.
False. Evaporation and crystallization are not the same processes. Correction: Evaporation completely vaporizes the solvent to obtain the solute, whereas crystallization is the process of forming pure solid crystals from a solution.
Explanation
The answers are evaluated based on the principles of separation techniques. (i) Salt is a non-volatile solute that can be separated from water by evaporation or distillation. (ii) Distillation relies on the difference in boiling points of the two miscible liquids; if they have the same boiling point, they will boil at the same temperature and cannot be separated. (iii) In paper chromatography, the liquid carries the substances up the paper, so the sample spot must be above the solvent level to prevent it from dissolving directly into the solvent pool. (iv) Evaporation dries up the solvent completely, while crystallization yields pure solid crystals from the solution.