n axit = 0,1 mol => CM CH3COOH = 0,1 M
CH3COOH <--> CH3COO- + H+ . Ka = $1,8.10^{-5}$
bd: 0,1M
pli:x.......................x...................x (M)
cb: 0,1-x............x.....................x
Ka = $\dfrac{x^2}{0,1-x}= 1,8.10^{-5}$
$=>x = 1,3327.10^{-3}$
[H+]= x= ....
pH= -log x =...
độ điện li = x/0,1 =....
b.
n muối= 0,45 mol => CM CH3COONa = 0,45 M
CH3COONa --> CH3COO- + Na+
0,45M ----------------> 0,45M
CH3COOH <--> CH3COO- + H+. Ka = $1,8.10^{-5}$
bd: 0,1M.................0,45M
pli: y..........................y...............y
cb: 0,1-y.................0,45+y.........y
Ka= $\dfrac{y(0,45+y)}{0,1-y}= 1,8.10^{-5}$
=> y => pH