aa

5.1.35.1.3.1 例如：H2SO4、HCO-、H3O+、NH H3O++Ac-=H2O+HAc +H H3O++OH-=H2O+注 5.1.4 Lewis

: A:Lewis 2H++:OH-=HOH++:NH2

A+:B→AR·+·R￠→R:R￠Red·+Ox→Red＋Ox－ H2O(l)+H2O(l)=H3O(aq)+OH wKqw

H+OHpH=-lg +=-lg pOH=-lg 25℃pH kkHAc+HHAc+HO=HO+23HAc=HaAc-Ac-+H2kqkbHO+HHO+HO=HO+223kw HAc+H2O=H3O

Ac-+H 2HO+HO=HO++OH- c+

KqKqb

KqH+OH HA=H++H 2HA-=H++HA2-HA2-=H++A3-2

KKKqK

+HO=HA2-+

KK2HA2-+HO=HA- 2 HA-+HO=HA+ Kq

=KqKq=KqKq=

H3O＋+

22

Kq

-Kq

- a+

1+K Ka=H=H+)2(）Kq/a0a￡5%a￡5%+)2K=a 500aKq0a/0a= /0H H

HA+HO=HO++H K KKHA-+HO=HO+ K aKHA2-+HO=HO+ K a KaHA+3HO=3HO+ Ka Kq=KqKqKq

H+H3 a akq a a - a1+ KqKq1022KqHa￡（或KqH

+

=4.30·10-7,Kq=5.61·10- HCO=H++ Kq0/Kq?500,Kq0

2-+

Ka2 2)H2C3

=Ka1Ka KqH

3 H3

a44NH++HO=HO+ + Kq+K=q K=

= Kq

10a-10a

110Kqb

- b+ a￡（或/Kq?50 >>kq>> b2 110Kq - b1+ a￡或/Kq?50

A3-+HO=OH- 2KKHA2-+HO=OH-+H 2KK bKHA-+HO=H K bA3-+3HO=H Kq Kq=KqKqKq

H3NH++Ac-+HO=NHH Kq NH++HO=NHH

Kq4a(NH+422Ac-+HO=HAc+OH-HO=H++OH-22

Kqb(Ac-KqKwKq Kq4Kq4

NH3

a(NH+ b(Ac- Kq4NH+ 4 K KK= b(NH3H2OK=K Kw

a(HAcKqK Kq Kq

b(NH3H2O

2=2

KqK =

( HAc)KKqKK

b(NH3H2O)

+Kq =

a(=KqwKqKq=KqKqwKqb(NH3H2O)Kqb(NH3H2O)5.4弱酸+弱酸鹽：HAc+NaAc弱堿+弱堿鹽：NH3e.g.HAc+ HAc=H+

KqKqH+Ac-0,bH+)H+a=H+?

-[H][H

+[H+a+ = a +

pOH=pKq

b-lgbwpH=pKq-w10:1pH=-lg apH=pKθ–abpOH=pKθ–b緩沖溶液只能將體系pH控制在pKθaa

保證一定的濃度0.05~0.5mol/L。H

H

Ka

HA2-

Ka

A3-K KKθKKK KKKθK

Kb