Question

The following are 1.0 M acid solution, which has the largest concentration of hydronium [H3O+]?

A. HNO2

B. H2CO3

C. H2SO4

D. H3BO3

Answer 1

H2SO4 has the largest concentration of hydronium [H3O+] because H2SO4 is a strong acid.

Answer 2

Answer: Option (C) is the correct answer.

Explanation:

An acid which is able to dissociate completely into ions in water is known as a strong acid.

For example, $H_{2}SO_{4} \rightleftharpoons 2H^{+} + SO^{2-}_{4}$

Therefore, sulfuric acid is a strong acid as it dissociates completely into ions in water.

Whereas $HNO_{2}$, $H_{2}CO_{3}$, and $H_{3}BO_{3}$ are all weak acids as they dissociates slightly in water as follows.

$H_{3}BO_{3} \rightleftharpoons H^{+} + H_{2}BO^{-}_{3}$

$HNO_{2} \rightleftharpoons H^{+} + NO^{-}_{2}$

$H_{2}CO_{3} \rightleftharpoons H^{+} + H_{2}CO^{2-}_{3}$

Morover, sufuric acid upon dissociation is giving 2 hydrogen ions and rest all are giving one hydrogen ion.

Thus, we can conclude that out of the given options $H_{2}SO_{4}$ has the largest concentration of hydronium [H3O+].