Answer
$C_5H_5NH^+$ is an acidic cation.
Work Step by Step
This is the "conjugate acid" type of acid.
- When you identify the $BH^+$ formula, where "$B$" represents a base:
1. Remove the $H^+$
$C_5H_5NH^+ -- \gt C_5H_5N$
2. If you don't know that it is a base,try to find this same formula on the $K_b$ values table, (Appendix III).
- This compound is there, its name is "pyridine", and it is a weak acid.
3. Therefore $C_5H_5NH^+$ is the conjugate acid of a weak base, pyridine, so, it is a weak acid.
