Final answer:
The first ionization step of carbonic acid can be represented by the equation H2CO3 + H2O -> H3O+ + HCO3-.
Step-by-step explanation:
The first ionization step of carbonic acid can be represented by the equation:
H2CO3 + H2O → H3O+ + HCO3-
The corresponding equilibrium expression for this reaction is:
Ka1 = [H3O+][HCO3-]/[H2CO3]