Differently strong acids behave identically strong in solvents where the conjugate acid formed is weaker than the said acids. This effect is called LE or solvent effect.
eg HCl and HNO3 show equal strength in their aqueous solutions. It is because either when added to water forms H3O+ ions- a conjugate acid. Both HCl and HNO3 are stronger than H3O+. So both are 100% converted to H3O+. So in the solution they both become H3O+ and lose their identity or identical strength. In other words, they are levelled by the solvent. So in aqueous solution we can't say which one is stronger.
HCl+H2O= H3O+ +Cl-
1 99 99
HNO3 +H2O = H3O+ + NO3
1 99 99
On the other hand, if we compare CH3COOH, a weaker acod then H3O+, withe HCl or HNO3, the former will be weaker. Because being weaker than H3O, it doesn't dissolve completely.
CH3COOH+H2O = H3O+ + CH3COO-
99 1 1
The same is the case for strong bases
Their strength too becomes indistinguishable in solutions where they form conjugate bases weaker than them.
No comments:
Post a Comment