What is the reaction of powdered sugar and water?

The reaction between powdered sugar and water is a dissolution reaction. When powdered sugar is added to water, the sugar molecules break down and become surrounded by water molecules. This process is called hydration. The water molecules form hydrogen bonds with the sugar molecules, holding them in solution. The resulting mixture is a sweet, syrupy liquid called simple syrup. Simple syrup is used as a sweetener in a variety of beverages and desserts.