Question

Assertion : Weak acids have very strong conjugate bases while strong acids have weak conjugate bases.
Reason : Conjugate acid-base pair differ only by one proton.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (B)

Strong acids such as perchloric acid $(HClO_4)$, hydrochloric acid $(HCl)$ give conjugate base ions $CIO_4^-$, $Cl^-$ which are much weaker bases than $H_2O$. On the other hand, a weak acid like acetic acid is only partially dissociated in aqueous medium and thus the solution mainly contains undissociated acetic acid which proves that $CH_3COO^-$ is stronger base than $H_2O$.