contestada

Which equilibrium system has HCO3- acting as a Brønsted-Lowry base?
HCO3- H+ + CO32-
HCO3- + HS- H2S + CO32-
HCO3- + H2S H2CO3 + HS-
HCO3- + H2O H3O+ + CO32-
HCO3- + O2- CO32- + OH-