The methanoate ion, HCO₂⁻ (aq) reacts with water to form methanoic acid and hydroxide ion, as shown in the following equation. HCO₂⁻ (aq) + H₂O (1) ←→ H,CO₂(aq) + OH⁻ (aq). Given that (OH⁻) is 4.18 x10⁻⁶ M in a 0.309 M solution of sodium methanoate, calculate each of the following. Show your work and answer with correct significant digits. The value of Kb for the methanoate ion, HCO²⁻ (aq).