In aqueous solution the ionization constants for carbonic acid are:
`K_(1)=4.2xx10^(-7)and K_(2)=4.8xx10^(-11)`
Select the correct statement for a saturated `0.034M` solution of the carbonic acid.

Options

A. The concentrations of `H^(+)` and `HCO_(3)^(-)` are approximately equal.
B. The concentration of `H^(+)` is double that of `CO_(3)^(-)`.
C. The concentration of `CO_(3)^(2-)` is 0.034 M.
D. The concentration of `CO_(3)^(2-) ` is greater than that of `HCO_(3)^(-)`.

Answer

A

Explanation

`H_(2)CO_(3)hArr H^(+)HCO_(3)^(-), K_(1)=4.2xx10^(-7)`
`HCO_(3)^(+)hArrH^(+)+CO_(3)^(2-),K_(2)=4.8xx10^(-11)`
As `K_(2)lt lt K`, concentrations of `H^(+)` and `HCO_(3)^(-)` will be approximately equal.