Answer:
The particle represented by X(aq) is A) H₂PO₄⁻(aq)
Step-by-step explanation:
According to the Brønsted-Lowry Theory, a base is a substance capable of accepting protons (H⁺) in solution. Conversely, a substance acts as an acid if it acts as a proton donor.
A proton transfer then occurs, requiring the presence of a proton donor (an acid) and a base that accepts them.
When an acid gives up a proton, it becomes an anion, generating a conjugate base. That is, a conjugate base is an ion or molecule resulting from the acid that loses the proton. Conversely, a conjugated acid is an ion or molecule resulting from the base that the proton gains.
In this NH₃ / NH₄⁺ pair that NH₄⁺ is the conjugate acid of the NH₃ base, the latter acting as a base since it accepts a proton. H₃PO₄ then acts as an acid, yielding a proton and generating the conjugate base H₂PO₄⁻.
So, the particle represented by X(aq) is A) H₂PO₄⁻(aq)