Question

In the following reaction

$HCO_{3}^{-}+H_{2}O\rightleftharpoons CO_{3}^{2 -}+H_{3}O^{+}$

Which two substances are Bronsted base?

• A. $CO_{3}^{2 -}$ and $H_{3}O^{+}$
• B. $HCO_{3}^{-}$ and $H_{3}O^{+}$
• C. $HCO_{3}^{-}$ and $CO_{3}^{2 -}$
• D. $CO_{3}^{2 -}$ and $H_{2}O$

Answer 1

Answer: (D)

Here $CO_{3}^{2 -}$ and $H_{2}O$ are Bronsted bases as water accept $H^{+}$ and $CO_{3}^{2 -}$ is the conjugate base of $HCO_{3}^{-}$ and as the reaction is reversible so $CO_{3}^{2 -}$ is accepting $H^{+}$ also.

$HCO_{3}^{-}+H_{2}O \rightleftharpoons CO_{3}^{2 -}+H_{3}O^{+}$