$HCOOH \rightleftharpoons HCOO^- + H^+$ $pH = 3 => [H^+] = 10^{-3}$
=> $\alpha = 0,001/0,007 = 0,143$
$K_{cb} = \frac{0,001.0,001}{0,006} = 1,67.10^{-4}$
khi pha loang $104 lần $C_{HCOOH} = 0,0007$
$HCOOH \rightleftharpoons HCOO^- + H^+$
Bd $0,0007$
pư $x $ $x$ $x$
CB $0,0007-x $ $x$ $x$
$K_{cb} = \frac{x.x}{0,0007-x} = 1,67.10^{-4} => x = 2,68.10^{-4}$
=> $\alpha = 2,68.10^-4/0,0007 = 0,383$
=> tỷ lệ