Question

What substance would you add to NaHCO₃(aq) to form a buffer solution?

1) HClO
2) NaF
3) NH₃
4) H₂CO₃
5) NaCl
6) NaOH

Answer 1

To create a buffer with NaHCO₃, H₂CO₃ should be added to form a buffer system consisting of a weak acid and its conjugate base.

Step-by-step explanation:

To form a buffer solution with sodium bicarbonate (NaHCO₃), you would need to add a substance that can provide either the corresponding weak acid or a salt with its conjugate base.

From the given list, carbonic acid (H₂CO₃) is a weak acid that forms when carbon dioxide dissolves in water and acts as the conjugate acid to the bicarbonate base.

Adding H₂CO₃ to NaHCO₃ creates a buffer solution consisting of a weak acid (H₂CO₃) and its conjugate base (HCO₃⁻), which can resist changes in pH when small amounts of acids or bases are added.