Overview

The miscibility of two liquids, their tendency to mix, depends in part on attractive forces between the molecules in each liquid. The hydroxyl group (-OH) found in water molecules and alcohol molecules creates relatively strong intermolecular forces called hydrogen bonds. The structural similarity between water and alcohols does not guarantee their miscibility, however. Some alcohols are completely miscible in water, while others are not.

In this experiment, you will attempt to measure the miscibility of several organic liquids, including several alcohols, with water. You will also try to explain trends in your data by constructing molecular models of your alcohols and looking for structure-related factors that might affect miscibility.

Time required: 1 laboratory session

space-filling molecular model of a methanol (CH₃OH)-water (H₂O) mixture