Which of the following is a typical drying agent used in organic chemistry?

In organic chemistry, drying agents are substances used to remove traces of water from organic solutions. Anhydrous magnesium sulfate is a widely accepted drying agent due to its effectiveness in absorbing water. It works by forming hydrated magnesium sulfate, effectively pulling moisture out of the organic solvent.

The ability of anhydrous magnesium sulfate to rapidly and efficiently dry organic solvents has made it a staple in laboratory settings. When added to a wet organic mixture, this dehydrating agent provides a large surface area for water molecules to adhere to, allowing for quick moisture removal.

In contrast, while the other options may have their uses in organic chemistry or other chemical contexts, they do not serve the primary purpose of a drying agent. Calcium carbonate and sodium chloride, for example, do not have the same water-absorbing capabilities as anhydrous magnesium sulfate, and potassium permanganate is primarily known for its oxidizing properties rather than water absorption. Thus, anhydrous magnesium sulfate stands out as the typical choice for effectively drying organic solvents in the laboratory.