2.1 DEFINITION OF SOLUTION, SOLVENT AND SOLUTE
When a small amount of sugar (solute) is mixed with water, sugar uniformally dissolves in water and a sugar solution is obtained. In this solution, sugar molecules are uniformly dispersed in molecules of water. Similarly, a common salt (NaCl) when dissolve in water, if uniformly disperse in water and salt + – solutions is obtained so a solution of salt in water consist of ions of salt (Na , Cl ) dispersed in water. Solutions are homogenous mixtures in which one substance is said to have been dissolved in the other. The dissolved substance may be present as individual molecules or ions throughout the other substance. Since both the components of a solution are present in the molecular or ionic state, it constitutes a perfectly uniform and transparent system.
Components of Solution
In the study of solution, it is customary to designate the components in solution. The components are:
Solvent The component present in larger proportion is known as solvent. Solute The component present in smaller proportion is known as solute. Solution = Solvent + Solute Ex. Sugar solution = Sugar (solute) + Water (solvent) Common salt solution = Salt (solute) + Water (solvent)
2.2 TYPES OF SOLUTION Homogenous Solution
A solution in which two substances are mixed has uniform composition and the components cannot be identified separately. Sugar (solute) S Sugar solutions — Two substances Ex. R Water (solvent)
A solution in which two or more substances are mixed has non-uniform composition and the components can be identified separately.
Naphthalene solution — Two substances
Naphthalene (solute) Water (solvent)
In naphthalene solution, both water and naphthalene can be identified and separated from one another and non-uniform in their properties like density, concentration and...