Sucrose or sugar (C12 H22 O11) crystals are composed of polar molecules. As the rule of thumb for solubility, “like dissolve like” suggests, water (H2O) being partially polar, dissolves sugar when mixed with it.

Sucrose, commonly known as “table sugar” or “cane sugar” is a disaccharide molecule. That molecule is made up of two monosaccharides, i.e. glucose and fructose.

why does sugar dissolve in water

These molecules are partially polar substances. This polarity is due to the presence of the hydroxyl (-OH) group. So these molecules interact with each other and they are held together in a crystal by weak intermolecular forces. Due to its slightly polar nature, when sugar is added to water it starts interacting with water molecules to form hydrated bonds.

As we know that whenever a bond is formed, it releases energy. In this case, that energy is consumed to break the crystal structure of sugar making it lose its lattice i.e. getting dissolved.

The above reasons make the solubility of sugar in water to be 180g / 100ml.