Define :(i) Buffer solution(ii) Solubility product(iii) Common ion effect

Answer:

(i) Buffer solution: A solution which resists a change in its pH when a small amount of a strong acid or a strong base is added to it (or when it is diluted) is called a buffer solution, e.g. CH₃COOH + CH₃COONa (acidic buffer), NH₄OH + NH₄Cl (basic buffer).

(ii) Solubility product: The solubility product (K_sp) of a sparingly soluble salt is the product of the molar concentrations of its ions in a saturated solution at a given temperature, each concentration raised to the power equal to the number of ions produced by one formula unit. For A_xB_y ⇌ xA^y+ + yB^x–, K_sp = [A^y+]^x[B^x–]^y.

(iii) Common ion effect: The suppression of the degree of dissociation of a weak electrolyte by adding a strong electrolyte that has an ion in common with it is called the common ion effect, e.g. the dissociation of CH₃COOH is suppressed by adding CH₃COONa.