What is pKa and what is the relation of pKa with acidity and basicity.
This pKa is something related to equilibrium constant, how let see. Let us consider the following reaction A + B ⇋ C + D in the above reaction initially some of A and B reacts to form C and D as products (In this reaction remember all the A and B are not converted to C and D).When the amount of C and D reaches a particular conentration the reaction goes to backward direction with the same rate as the forward reaction goes on. In these types of reaction the composition of reaction mixture remains constant in a particular physical conditions. For the above reaction:- equlibrium constant , Keq = [A][B]/[C][D] A],[B],[C],[D] are the concentrations of A,B,C and D respectively. If there is a reaction is in equilibrium involving acid in water then: AH + H 2 O ⇋ A - + H 3 O + ...................(eq 1) For this the equilib