Final answer:
The conjugate acid of HA- is formed by adding a proton to it, resulting in HA. Thus, the correct formula for the conjugate acid of HA- is HA (option 2 is correct.)
Step-by-step explanation:
The conjugate acid of HA- is formed by adding a proton (H+) to HA-, which is its conjugate base. To determine the correct conjugate acid, we add one hydrogen ion (H+) to the base (HA-), resulting in HA. Therefore, the conjugate acid of HA- is HA, and the correct answer is option 2) HA.
The formula of the conjugate acid of HA- is H₂A.
When an acid loses a proton, it forms its conjugate base, and when a base accepts a proton, it forms its conjugate acid. In this case, HA- is the conjugate base of the acid H2A, so the conjugate acid of HA- would be H2A.
Example:
If we have the weak acid H2A, it can lose a proton to form its conjugate base HA-. The conjugate acid of HA- would then be H2A.