The basicity of \(H_3PO_4\)

3

The correct answer is option 3. 3.

The basicity of an acid refers to the number of hydrogen ions (protons, \( \text{H}^+ \)) that the acid can donate in an aqueous solution.

\(H_3PO_4\) (Phosphoric Acid):

The chemical formula for phosphoric acid is \( \text{H}_3\text{PO}_4 \). Phosphoric acid has three hydrogen atoms that are capable of being donated as \( \text{H}^+ \) ions.

Ionization Steps:

Phosphoric acid ionizes in three steps, each releasing one hydrogen ion:

\( \text{H}_3\text{PO}_4 \) → \( \text{H}^+ \) + \( \text{H}_2\text{PO}_4^- \)

\( \text{H}_2\text{PO}_4^- \) → \( \text{H}^+ \) + \( \text{HPO}_4^{2-} \)

\( \text{HPO}_4^{2-} \) → \( \text{H}^+ \) + \( \text{PO}_4^{3-} \)

Each step corresponds to the loss of one proton, meaning \( \text{H}_3\text{PO}_4 \) can donate three protons in total.

Basicity of \( H_3PO_4 \):

The basicity of \( \text{H}_3\text{PO}_4 \) is therefore 3, as it can donate three protons.