Question

It always dissociates completely in aqueous solution. It is called as:

• A. a Bronsted acid
• B. a strong acid
• C. a weak base
• D. a buffer

Answer 1

The correct option is B a strong acid

(A) A Bronsted acid donates $H^{+}$, therefore a weak $H^{+}$ donor can be a Bronsted acid. For example $H_{2}O$ donates weakly to $N{H}_3$. They can't dissociate completely.

(B) A strong acid like $H_{2}S{O}_4,HN{O}_3,HCl$ dissociates completely to give $H^{+}$.

$H_{2}S{O}_4\rightleftharpoons 2H^{+}+S{O}_4^{2-}$ ; $HN{O}_3\rightleftharpoons H^{+}+N{O}_3^{⊝}$

(C) A weak base like $N{H}_{4}OH$ can't dissolve completely.

(D) Buffer contains a weak acid and its' salt or a weak base and its' salt. So they can't completely dissociate.