Total ionic and net ionic equations

Question

I need help with figuring out the total ionic equations and net ionic equations for:

the addition of an acid to a buffer solution of NaHCO3 + Na2CO3

and the addition of a base to a buffer solution of NaHCO3 + Na2CO3

Answer 1

In the buffer system of NaHCO₃ + Na₂CO₃, HCO₃^- (NaHCO₃) acts as the weak acid, CO₃^2- (Na₂CO₃) acts as the conjugate base.

When acid (HCl) is added, it will react with the conjugate base Na₂CO₃ to produce the weak acid NaHCO₃.

Na₂CO₃(aq) + HCl(aq) ==> NaCl(aq) + NaHCO₃(aq) ... molecular equation

2Na⁺(aq) + CO₃^2-(aq) + H⁺(aq) + Cl^-(aq) ==> 2Na⁺(aq) + Cl^-(aq) + HCO₃^-(aq) ... total ionic equation

CO₃^2-(aq) + H⁺(aq) ==> HCO₃^-(aq) ... net ionic equation

When base (NaOH) is added, it will react with the acid NaHCO₃ to produce the conjugate base Na₂CO₃.

NaHCO₃(aq)+ NaOH (aq) ==> H₂O(l) + Na₂CO₃(aq) ... molecular equation

Na⁺(aq) + HCO₃^-(aq) + Na⁺(aq) + OH^-(aq) ==> H₂O(l) + 2Na⁺(aq) + CO₃^2-(aq) ... total ionic equation

HCO₃^-(aq) + OH^-(aq) ==> H₂O(l) + CO₃^2-(aq) ... net ionic equation