Which method is commonly used to dry organic solvents?

Using drying agents such as anhydrous magnesium sulfate is the standard method for drying organic solvents. When organic solvents are exposed to moisture, especially if they contain water, the drying agents can absorb this water effectively due to their high affinity for it. Anhydrous magnesium sulfate, in particular, is a versatile drying agent that selectively binds water, leaving the organic solvent free of moisture. This process typically involves adding the drying agent to the solvent, allowing sufficient time for it to absorb water, and then filtering out the solid drying agent, resulting in a dry organic solvent ready for further use in reactions or analyses.

Other methods such as heating lamps or evaporating at room temperature might not effectively remove all water, which can affect the purity and reactivity of the solvent. Stirring with sand is not a recognized method for drying organic solvents and would not effectively remove moisture.