Final answer:
The nature of an aqueous HCO⁻³ solution as acidic, basic, or neutral depends on the hydronium ion concentration relative to hydroxide ions, but there is not enough information provided to determine this.
Step-by-step explanation:
An aqueous solution of HCO⁻³ (bicarbonate ion) at 25°C can be acidic, basic, or neutral depending on its concentration relative to hydronium (H3O+) and hydroxide (OH−) ions. The bicarbonate ion acts as a weak base when it reacts with water, forming hydroxide ions.
Hence, a solution containing HCO⁻³ will be basic if the hydronium ion concentration is less than 1.0 × 10⁻⁷ M. Therefore, given the lack of explicit concentration values in the question, we do not have sufficient information to definitively say whether the solution is acidic, basic, or neutral.