Suppose a buffer solution is made of formic acid (HCHO2) and sodium formate (NaCHO2). What is the net ionic equation for the reaction that occurs when a small amount of HCl is added to the buffer?

Question

Suppose a buffer solution is made of formic acid (HCHO₂) and sodium formate (NaCHO₂). What is the net ionic equation for the reaction that occurs when a small amount of HCl is added to the buffer?

A. H⁺(aq) + OH^-(aq) → H₂O(l)

B. H⁺(aq) + HCHO₂(aq) → H₂O(l) + H₂CHO₂⁺(aq)

C. HCl(aq) + OH^-(aq) → H₂O(l) + Cl^-(aq)

D. HCl(aq) + CHO₂^-(aq) → HCHO₂(aq) + Cl^-(aq)

E. H⁺(aq) + CHO₂^-(aq) →  HCHO₂(aq)

Answer 1

The small amount of HCl (H+) will react with the NaCHO₂ (CHO₂^-) to form the weak acid (HCHO₂).

The net ionic equation will be:

H⁺(aq) + CHO₂^-(aq) ===> HCHO₂(aq) ... Equation E from the list

The complete molecular equation will be:

HCl(aq) + NaCHO₂(aqO ==> NaCl(aq) + HCHO₂(aq)