Question

Conjugate acid of a weak base is always stronger. What will be the decreasing order of basic strength of the following conjugate bases?

$$\mathrm{OH}{\phantom{A}}^{-},\mathrm{RO}{\phantom{A}}^{-},\mathrm{CH}{\phantom{A}}_3\mathrm{COO}{\phantom{A}}^{-},\mathrm{Cl}{\phantom{A}}^{-}$$

Answer 1

As the Conjugate acid of a weak base is always stronger and conjugate base of weak acid is always strong.

The weak acids are:

⇒ $$\mathrm{H}{\phantom{A}}_2\mathrm{O},\mathrm{ROH},\mathrm{CH}{\phantom{A}}_3\mathrm{COOH},\mathrm{HCl}$$

⇒ $$\mathrm{HCl}>\mathrm{CH}{\phantom{A}}_3\mathrm{COOH}>\mathrm{ROH}>\mathrm{H}{\phantom{A}}_2\mathrm{O}$$

⇒ Conjugate base order ⇒ $$\mathrm{OH}{\phantom{A}}^{-}>\mathrm{RO}{\phantom{A}}^{-}>\mathrm{CH}{\phantom{A}}_3\mathrm{COO}{\phantom{A}}^{-}>\mathrm{Cl}{\phantom{A}}^{-}$$