0.005M कोडीन `(C_18H_21NO_3)` विलयन की pH 9.95 है। इसका आयनन स्थिरांक ज्ञात कीजिए।

Explanation

`Cod + H_2O iff CodH^(+) + OH^-`
`pH = 0.95, OH = 14-9.95 = 4.05 , - log [OH^(-)] = 4.05`
`log[OH^-] = -4.05 = bar5.95`
`OH^- = "antilog" bar(5).95 = 8.913 xx 10^(-5)`
`K_b = ([CodH^+][OH^-])/([Cod]) = ([OH^-]^2)/([Cod]) = ((8.91 xx 10^(-5) )^2)/((5 xx 10^(-3)) = 1.588 xx 10^(-6)`
`pK_b = -log K_b = -log (1.588 xx 10^(-6)) = (6-log 1.588) = 6-0.1987 = 5.8`