0.001M एनीलीन विलयन का pH क्या है? एनीलीन का आयनन स्थिरांक सारणी 7.7 से ले सकते हैं। इसके संयुग्मी अम्ल का आयनन स्थिरांक ज्ञात कीजिए।

Explanation

(i) `C_6H_5NH_2 + H_2O iff C_6H_5 NH_3^(+) + OH`
`K_a = ([C_6H_5NH_4^+][OH^-])/([C_6H_5NH_2][H_2O]) = ([OH^-]^2)/([C_6H_5NH_2])`
`[OH^-] = [K_a xx (C_6H_5NH_2)]^(1//2) =[(4.27 xx 10^(-10) ) (10^(-3) )]^(1//2)`
` = 6.534 xx 10^(-7)M`
`pOH = -log (6.534 xx 10^(-7) ) = (7 - log 6.534) = (7 - 0.8152) = 6.18`
`pH =14-6.18 = 7.82`

`K_b = ( Calpha C alpha)/(C(1-alpha)) = (Calpha^2)/(1 - alpha) = C alpha^2 rArr alpha = ((K_b)/(C))^(1//2)`
`alpha = (4.27 xx (10^(-10) )/(10^(-3) ))^(1//2) = 6.53 xx 10^(-4)`
(iii) `pK_a + pK_b = 12 ` (संयुग्मी अम्ल, क्षार युग्म के लिए)
`pK_b = -log K_b = -log (4.27 xx 10^(-10)) = (10 -log 4.27)`
`= 10.0.62 = 9.38`
`pK_a = 14 -pK_b= 14 - 9.38 = 4.62`
`pK_a = -log K_a = 4.62 rArr log K_a = -4.62 = 5.38`
`K_a = Antilog (bar5.38) = 2.399 xx 10^(-5) = 2.4 xx 10^(-5)`