Solution is a homogeneous mixture of two or more than two components which can be separated by a suitable physical method. By homogeneous we mean that the solution has a uniform composition.
If the solution has two components then it is called a binary solution. If it has three solutions then it is called a ternary solution.
The component present in the larger amount is called solvent while the other component(s) are called solute(s).
Depending upon the physical state (solid, liquid, gas) we can have nine types of solutions.
| Type Of Solution | Solvent | Solute | Example |
| Gaseous Solutions | Gas | Gas | Air |
| Liquid | Moisture(water in air) | ||
| Solid | Camphor in nitrogen gas | ||
| Liquid Solutions | Liquid | Gas | Oxygen dissolved in water |
| Liquid | water and ethanol | ||
| Solid | Salt in water | ||
| Solid Solutions | Solid | Gas | Hydrogen gas in palladium |
| Liquid | sodium amalgam | ||
| Solid | Brass (Zn + Cu) |
Solid solutions having solid solute and solid solvent are specially important in industries. They are of two types:
1. Substitutional solid solutions: In these type of solid solutions the particle size of the components is similar and they can occupy each other's lattice positions. e.g. brass, bronze
2. Interstitial solid solutions: In these type of solid solutions the particle size of the components are very much different from each other. The smaller particles occupy the interstitial space or voids in the lattice of the other component. e.g. tungsten carbide, WC.
