Final answer:
A solution of phosphoric acid (H₃PO₄) has a pH less than 7, making it an acidic solution, but the appropriate description in this context is that it can act as a triprotic acid, due to its ability to release three protons into the solution.
Step-by-step explanation:
A solution of phosphoric acid (H₃PO₄) can exhibit a variety of characteristics based on its properties. Phosphoric acid is an oxyacid and is known to be triprotic, meaning it has three hydrogen ions (protons) that can dissociate in a solution. The dissociation of these hydrogens occurs in steps, with each hydrogen ion released decreasing the pH of the solution. It is important to note that phosphoric acid is not a strong acid like hydrochloric acid, but is moderate in strength and therefore does not ionize completely in solution. Nonetheless, as an acid, a solution of phosphoric acid will have a pH less than 7. It does not exhibit basic properties because its solutions are acidic due to the liberation of hydronium ions.
The successive ionization constants for phosphoric acid indicate that each proton is released less readily than the previous one, which is a common characteristic of polyprotic acids. Calculations of equilibrium concentrations in a solution of H₃PO₄ can be simplified due to the significant difference in ionization constants between each proton release. Finally, when phosphoric acid is added to soft drinks, it provides a tangy flavor and also acts as a preservative due to its acidic properties. Therefore, on the basis of its ability to release multiple protons and resulting in an acidic solution, the correct option for the given question is can act as a triprotic acid.