PH calculations thanks?

Question

1. Dissolved CO2 acts as a weak acid in water according to the equation

CO2(aq) + H2O(l)---> H+(aq) + HCO3–(aq)

and the acidity constant of CO2 in water at 25°C is given by 4.5 × 10–7M2

Some CO2 is added to a solution of NaHCO3 at 25°C. In the solution, the concentration of the hydrogen carbonate ions (HCO3–) is 0.050 M and the CO2 concentration is 0.0020 M. Calculate the pH of the solution.

In this question isn't the concentration of HCO3–(aq) equal to H+(aq) because their being produced at the same rate? Therefore why can't you just put the .05M straight into -log10 when calculating the pH?

Answer 1

the concentration of Hydrogen in HCO3- is .03M ... there for H+ should be .03M...