Introduction to solution: Is there existence of life outside of our planet earth? Often a question is asked. This search of existence of life is going on for last so many years. The appearance of unidentified flying objects in the sky is the only supportive evidence for the existence of life outside the earth. The life on our planet is possible because it is surrounded by air which contains the gas oxygen, called ‘Pranvayu’ without which PRAN (Life) is not possible.
In addition, two third of the earth is covered with water, the most essential, vital component for life. Water is called JEEVAN meaning life. Water in the sea is not in pure form. It contains sodium chloride, magnesium chloride, calcium salts and gases like oxygen, carbon dioxide in dissolved state. Some of these dissolved components reacted chemically in presence of oxygen and sunlight, and life was originated, developed in sea water, a solution.
Solution consists of least two components, a medium and dissolved phase. In this unit it is desired to study the properties of solutions. The physical properties of solution are mainly originated by intermolecular forces of attraction between the solvent molecules. Theses intermolecular forces of attraction are changed by the presence of dissolved substances.
The physical properties include vapour pressure, boiling point, freezing point and osmotic pressure.
The study of chemistry is incomplete without the study of solutions. Solutions are the mixtures of two or more components. Depending on sizes of the components. Most chemical reactions are carried out in solutions. Neutral water for example sea water or ocean water, river – water, lake- water are actually the solutions of many salts in water. Body – fluids are also solutions of various components in water. Solutions are thus integral part of the animal and vegetable kingdom. In this chapter, we describe certain important properties of solutions.