Intrinsic Strength of Acids and Bases

Intrinsic Strength of Acids and Bases

The strength of acids and bases are not same. The strength of acids can be predicted on the basis of radius, oxidation state, formal charge and effective nuclear charge on oxygen in oxyanion. The strength of hydroxides depends on radius of anion and oxidation state of the non metal, strength of oxyacids depends on formal charge, effective charge on oxygen and central non-metal radius in the oxy anion.
Greater the radius of X, greather the H-X bond length, lower is H-X bond strength, greater is dissociation of H-X to H⁺ + X⁻, greater is H⁺ concentration in solution so, greater the strength of the acid.
Acidic strength-
HF < HCl < HBr < HI
H₂O < H₂S < H₂Se < H₂Te