Why is nahco3 a base?

(i need someone to explain it using the ka values)

h2co3 < --> hco3- + h+ ka = 4.3x10^-7
hco3- < --> co3^2- + h+ ka = 5.61x10^-11

if i underestand correctly, the kb for the second equation is greater than the ka. thus the reaction will not proceed forward, but rather produce more hco3-. this is a basic tendency. why is it more powerful than the first reaction?

Will give ! what are the advantages and disadvantages of nuclear power? check all that apply. one advantage of nuclear energy is that it does not produce carbon dioxide emissions. storage of nuclear waste is a short-term problem associated with nuclear energy. the problem with uranium mining is that a large quantity of uranium must be extracted to meet energy needs because the energy release from uranium fission is so low. safe operation of a nuclear power plant can be jeopardized by a human mistake.