In aqueous solution the ionization constants for carbonic acid are : $K_{1} = 4.2 \times 10^{- 7}$ and $K_{2} = 4.8 \times 10^{- 11}$
Select the correct statement for a saturated $0.034 M$ solution of the carbonic acid.

see full answer

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!

An Intiative by Sri Chaitanya

The concentration of $H^{+}$ is double that of ${CO}_{3}^{2 -}$

The concentration of ${CO}_{3}^{2 -}$ is $0.034 M$

The concentration of $H^{+}$ and ${HCO}_{3}^{-}$ are approximately equal

The concentration of ${CO}_{3}^{2 -}$ is greater than that of ${HCO}_{3}^{-}$

answer is C.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

For the carbonic acid of saturated $0.034 M$ solution,

$\begin{array}{l} [H_{2} {CO}_{3}] = 0.034 \\ = [{CO}_{3}^{2 -}] + [{HCO}_{3}^{-}] \end{array}$

$[{CO}_{3}^{2 -}] < [H {CO}_{3}^{-}]$ because $k_{1} >> k_{2}$

$[H^{+}] ≅ [{HCO}_{3}^{-}]$

Thus, the concentration of $H^{+}$ and ${HCO}_{3}^{-}$ are approximately equal.

Watch 3-min video & get full concept clarity