Answer:
Acid: HCN
Base: CO₃²⁻
Step-by-step explanation:
HCO−3 is amphoteric, which means it may act as an acid or a base depending on the other reactant.
CN− cannot be an acid because it does not contain hydrogen. A negative charge is often indicative of a Brønsted‑Lowry base. As a base, CN− will accept H+ to form the conjugate acid HCN.
Because CN− is a base, HCO−3 will behave as an acid. As an acid, HCO−3 will donate H+ to form the conjugate base CO2−3.
HCO−3+CN−↽−−⇀HCN+CO2−3