Which of the following is most soluble in water?

Solubility is the ability of a substance to dissolve in a solvent and form a uniform solution. Water is called the universal solvent because it can dissolve a wide variety of substances due to its polar nature and capability to form hydrogen bonds with solute molecules.

The given substances — Camphor, Sulphur, Common salt (NaCl), and Sugar (sucrose) — have different solubility characteristics:

1. 
   

   Camphor is a nonpolar organic compound. It is only slightly soluble in water, but dissolves better in organic solvents like alcohol or ether.

   
   


2. 
   

   Sulphur is nonpolar and essentially insoluble in water.

   
   


3. 
   

   Common salt (NaCl) is ionic and dissolves well in water due to ion-dipole interactions, but at room temperature, its solubility is around 36 g per 100 mL of water.

   
   


4. 
   

   Sugar (sucrose) is a polar molecular compound. Its molecules form extensive hydrogen bonds with water, making sugar highly soluble, much more than NaCl at standard conditions (about 200 g per 100 mL of water at 20°C).

   
   

Because sugar dissolves in water in larger amounts than the other options, it is considered the most soluble substance among them. This concept is important in chemistry because it explains how substances interact with solvents, how solutions are prepared, and how solubility influences industrial processes, food chemistry, and biological systems.

Understanding solubility also helps in predicting reaction rates, saturation levels, and crystallization processes. Observing everyday examples, such as sweetened drinks or sugar in cooking, demonstrates how molecular structure affects solubility. Polar molecules like sugar dissolve readily in water because of the strong attraction between water molecules and the solute.

This knowledge is fundamental in Chemistry, linking theory to practical applications in food, pharmaceuticals, and laboratory experiments.