Core Tips

• We use many substances in liquid form in day to day life.
• A mixture of two or more substances is called a solution in broad sense. The component present in smaller proportion is called a solute while the component present in larger proportion is called a solvent.
• Conventionally, a homogeneous mixture of solute and solvent is called a solution.
• When water is used as a solvent, the solution is called an aqueous solution. When the solvent is other than water then the solution is called non–aqueous solution.
• Solutions can be classified on the basis of physical state of solute and solvent. Accordingly, there are seven types of solutions.
• In 1887, Arrhenius first put forth his theory of electrolytic dissociation in water.
• Arrhenius defined a compound which contains H+ ion and liberates H+ ion in water as acid and a compound which contains OH− ion and liberates OH− ion in water as alkali.
• Base is a compound which reacts with an acid to form salt.
• An acid or base which dissociates in water to a large extent is called a strong acid or strong base and that which dissociates in water to a small extent is called a weak acid or weak base.
• The number of hydrogen ions in one molecule of an acid is called the basicity of the acid and the number of hydroxyl ions in one molecule of an alkali or base is called the acidity of the base.
• Equivalent weight of an acid and base can be found out from their molecular weight and acidity and basicity of the compound.
• There are different methods of expressing concentration of a solution like mass percent, ppm, normality, molarity, molality etc.
• Normality is inversely proportional to volume of the solution.