Question

Calculate the hydronium ion concentration in an aqueous solution of 0.165 M carbonic acid, H,CO, (aq). [H20"]= M. Submit Answer Retry Entire Group 4 more group attempts remaining

Answer 1

Ka1 of H2CO3 = 4.3*10^-7

H2CO3 <----> H+   + HCO3-

0.165          -       -

- x        + x    +x

0.165-x       x    x

Ka1 = [H+][Hco3-]/[H2co3]

(4.3*10^-7) = x*x/(0.165-x)

x = 2.66*10^-4

[HCO3-] = x = 2.66*10^-4 M

The concentration of H3O+ depends upon mainly on Ka1 only but not on Ka2.