Chemistry – Experimental techniques and chemical analysis - Separation and purification | e-Consult

Description: Separation using a suitable solvent, also known as dissolution, involves dissolving a solid substance in a solvent to separate it from impurities. The desired substance is then recovered from the solution by evaporation of the solvent.

Explanation: The success of this method relies on the principle that different substances have different solubilities in different solvents. A suitable solvent is one that:

• Dissolves the desired substance readily.
• Does not dissolve the impurities.
• Is easily removed (e.g., by evaporation).
• Is non-toxic and inexpensive.

Factors to consider when choosing a solvent: The polarity of the solvent is crucial. "Like dissolves like" – polar solvents dissolve polar substances, and non-polar solvents dissolve non-polar substances. The boiling point of the solvent is also important for ease of removal.

Advantages: Relatively simple and inexpensive. Can be used to separate a large amount of material.

Disadvantages: May not be effective if impurities have similar solubilities to the desired substance. Can lead to loss of product if the solvent is volatile. Requires careful selection of a suitable solvent.