※ 引述《runnial (呵呵)》之銘言：
: Pyridine, C5H5N, is a weak base and reacts with HCL as follows:
: C5H5N + HCL --> C5H5NH+ + Cl-
這個式子只是要告訴你C5H5NH+如何形成
形成後在水溶液中主要的離子就是C5H5NH+, Cl-
其中Cl-不水解
所以只要考慮C5H5NH+的水解就好
: What is the PH of a 0.015 M solution of the pyridinium ion(C5H5NH+)?
: The Kb for pyridine is 1.6*10^-9
: 可以告訴我如何解題嗎?謝謝
C5H5NH+水解：
C5H5NH+ + H2O → C5H5N + H3O+
└───────┘
共軛酸鹼對：Ka = Kw/Kb
[H+]*[A-] Kw
由 Ka = ────── = ──
[HA] Kb
[H+]^2 10^(-14)
=> ──── = ───────
0.015 1.6 * 10^(-9)
=> [H+] = 3.06 * 10^(-4)
=> pH = -log[H+] = 3.51 (離7很遠，所以不用考慮水的自解離)
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