Why is 1,2-dichloroethane a better solvent for caffeine extraction than water?

Answer is in the explanation

Explanation:

In an extraction process, you want to take the higher amount of a compound. You can make this due solubility of the compound in a particular solvent.

The higher solubility of the compound in the solvent, the higher extraction of the compound from the original mixture.

Solubility of caffeine in water is about 16mg/mL in water at room temperature. But in 1,2-dichloroethane is about 100mg/mL.

Thus, the reason of the better extraction with 1,2-dichloroethane is because of  the high solubility of caffeine in this solvent.