(1.32 10 5)2
(H2A) =0.145
(1.32 10 5)2 6.46 10 5 1.32 10 5 2.69 10 6 6.46 10 51.32 10 5 6.46 10 5
1(HA)
(1.32 10 5)2 6.46 10 5 1.32 10 5 2.69 10 6 6.46 10 5
=0.710
6.46 10 5 2.96 10 6
0(A)
(1.32 10 5)2 6.46 10 5 1.32 10 5 2.69 10 6 6.46 10 5
2
=0.145
pH=5
(1.0 10 5)2
=0.109 (H2A) 52 5 5 6 5
(1.0 10) 6.46 10 1.0 10 2.69 10 6.46 101.0 10 5 6.46 10 5
=0.702 1(HA)
(1.0 10 5)2 6.46 10 5 1.0 10 5 2.69 10 6 6.46 10 5
6.46 10 5 2.96 10 6
=0.189 0(A) 52 5 5 6 5
(1.0 10) 6.46 10 1.0 10 2.69 10 6.46 10
2
pH=4.88 c(H2A)=0.01mol·L-1 c(H2A)=0.145×0.01=1.45×10-3mol·L c(HA-)=0.710×0.01=7.10×10-3mol·L c(A2-)=0.145×0.01=1.45×10-3mol·L-1
4.4 分别计算H2CO3(pKa1=6.38，pKa2=10.25)在pH=7.10，8.32及9.50时，H2CO3，HCO3-和CO32-的分布系数δ2` δ1和δ0。 解：pH=7.10
(10 7.10)2
=0.16 2(H2CO3) 7.102 6.38 7.10 10.25 6.38
(10) 10 10 10 1010 7.10 10 6.38
=0.84 1(HCO)
(10 7.10)2 10 6.38 10 7.10 10 6.38 10 10.25
3
10 6.38 10 10.25-4
=5.94×10 0(CO)
(10 7.10)2 10 6.38 10 7.10 10 6.38 10 10.25
2 3
pH=8.32
(10 8.32)2
=0.0112 2(H2CO3)
(10 8.32)2 10 6.38 10 8.32 10 10.25 10 6.3810 8.32 10 6.38
=0.979 1(HCO) 8.322 6.38 8.32 6.38 10.25
(10) 10 10 10 10
3
10 6.38 10 10.25
=0.0115 0(CO)
(10 8.32)2 10 6.38 10 8.32 10 6.38 10 10.25
2 3
pH=9.50