physical state of the solute and the solvent We know that substances normally exist in three physical states (phases) i.e., solid, liquid and gas. In binary solutions, both the solvent and solute may exist in any of these physical states. But the solvent constitutes the major part of the solution. Its physical state is the primary factor which determine the characteristics of the solution.
Therefore, there are different types of binary solutions as listed in Table . . . .
Based on the type of solvent Most of the substances are soluble in water. That is why, water is called as ‘Universal solvent”. However some substances do not dissolve in water. Therefore, other solvents such as ethers, benzene, alcohols etc., are used to prepare a solution.
On the basis of type of solvent, solutions are classified into two types. They are aqueous solutions and non-aqueous solutions. a) Aqueous solution: The solution in which water acts as a solvent is called aqueous solution. E.g.
Common salt in water, Sugar in water, Copper sulphate in water etc. b) Non – Aqueous solution: The solution in which any liquid, other than water, acts as a solvent is called non- aqueous solution. Solvent other than water is referred to as non-aqueous solvent. Generally, alcohols, benzene, ethers, carbon disulphide, acetone, etc., are used as non-aqueous solvents.
Examples for non-aqueous solutions: Sulphur dissolved in carbon disulphide, Iodine dissolved in carbon tetrachloride. Table . Types of binary solutions Solute Solvent Example Solid solution Solid Solid Copper dissolved in gold (Alloys) Liquid Solid Mercury with sodium (amalgam) Liquid solution Solid Liquid Sodium chloride dissolved in water Liquid Liquid Ethyl alcohol dissolved in water Gas Liquid carbon-di-oxide dissolved in water (Soda water) Gaseous solution Liquid Gas Water vapour in air (cloud) Gas Gas Mixture of Helium-Oxygen gases,