Question

In the following reaction, H3PO4 (aq) + H2O (l) ⇄ H2PO4– (aq) + H3O+ (aq) what happens when more H2PO4– (aq) is added to the solution?

Answer 1

The concentration of H₃PO₄ will increase.

Step-by-step explanation:

H₃PO₄(aq) + H₂O(l) ⇄ H₂PO₄⁻(aq) + H₃O⁺(aq)

According to Le Châtelier's Principle, when we apply a stress to a system at equilibrium, the system will respond in a way that tends to relieve the stress.

If we add more H₂PO₄⁻, the position of equilibrium will move to the left to get rid of the added H₂PO₄⁻.

The concentration of H₃PO₄ will increase.