Question

Phosphoric acid is a triprotic acid. Write the ionization equation(s) and circle any species that are amphoteric.

Answer 1

Answer:

$\mathbf{H_2PO^{-}_4}$  and $\mathbf{HPO^{2-}_4}$ are the amphoteric species.

Explanation:

Phosphorus is a non-metallic element belonging to Group 5 of the Periodic table. As a triprotic acid (i.e an acid that has three dissociable protons that undergo stepwise ionization) . Phosphorus reacts vigorously with hot water to form tetraoxosulphate(V) acid.

i.e

$P_4O_{10(s)} + 6 H_2O_{l} \to4H_3PO_{4(aq)}$

SO;

As a triprotic acid;

The ionization equations are as follows:

NOTE: Instead of the amphoteric species  to be circle as instructed , due to the fact that we are using the LaTex Editor ; we will just need to let them be in bold format which will differentiate them from the rest.

$H_3PO_{4} \leftrightarrow H^+ + H_2PO^{-}_4$

$\mathbf{H_2PO^{-}_4} \leftrightarrow H^+ + HPO^{2-}_4$

$\mathbf{HPO^{2-}_4} \leftrightarrow H^+ + PO^{3-}_4$

Thus; $\mathbf{H_2PO^{-}_4}$  and $\mathbf{HPO^{2-}_4}$ are the amphoteric species.