What Property Of Water Causes Sugar To Dissolve In Coffee?

Answer 1

Water is a polar solvent. Each individual water molecule has a slightly positive charge on one side and a negative charge on the other. This is called an electric dipole. Charged molecules tend to dissolve in water, whereas uncharged molecules do not. Sucrose (table sugar) has many electric dipoles all around its three-dimensional structure. This makes it soluble in water. And coffee.

Answer 2

The solubility of a solute in a solvent is based on (a) similar polarities between them ("like-dissolves-like" principle), (b) the formation of solute-solvent interactions, and (c) temperature. In your question, sugar is the solute and water (in preparing coffee) is the solvent.

(a) Water and sugar are both polar, hence, sugar can dissolve in water.

(b) Water and sugar form hydrogen bonding interactions, which are fairly strong and stable.

(c) Temperature: Solubility of a solute in a solvent generally increases with temperature. As a result, sugar is more soluble in hot coffee compared to cold coffee.