The buffer solution contains the following species in solution: HCHO2(aq), HCO2-(aq), Na+(aq) When NaOH is added, the OH- ions react with formic acid to give formate ions and water. It is an acid-base neutralization reaction (weak acid and strong base). The net equation is given by: OH-(aq) + HCHO2(aq) => HCO2-(aq) + H2O(l) Solution The buffer solution contains the following species in solution: HCHO2(aq), HCO2-(aq), Na+(aq) When NaOH is added, the OH- ions react with formic acid to give formate ions and water. It is an acid-base neutralization reaction (weak acid and strong base). The net equation is given by: OH-(aq) + HCHO2(aq) => HCO2-(aq) + H2O(l).