1
鍥涚珷
缂撳啿婧舵恫
棣?/p>
椤?/p>
闅鹃瑙ｆ瀽
瀛︾敓鑷祴棰?/p>
瀛︾敓鑷祴绛旀
绔犲悗涔犻绛旀
闅鹃瑙ｆ瀽
[TOP]
渚?/p>
4-1
鐜版湁
1.0L
缂撳啿婧舵恫锛屽唴鍚?/p>
0.01mol H
2
PO
4
-
銆?/p>
0.030mol HPO
4
2-
銆?/p>
锛?/p>
1
锛?/p>
璁＄畻璇ョ紦鍐叉憾娑茬殑
pH
锛?/p>
锛?/p>
2
锛?/p>
寰�璇ョ紦鍐叉憾娑蹭腑鍔犲叆
0.005 0 mol HCl
鍚庯紝
pH
绛変簬澶氬皯锛?/p>
鏋?/p>
棰樿缂撳啿绯伙細
H
2
PO
4
-
HPO
4
2-
+ H
+
锛岀敤鍏紡
pH
锛?/p>
p
K
a
+lg
)
PO
(H
)
(HPO
4
2
2
4
飥?
飥?
n
n
璁＄畻銆傝嫢鍔犲叆
HCl
锛?
H
+
涓?/p>
HPO
4
2-
鍙嶅簲鐢熸垚
H
2
PO
4
-
銆?/p>
瑙?/p>
锛?/p>
1
锛夋牴鎹?/p>
H
3
PO
4:
p
K
a1
=2.16;
p
K
a2
=7.21;
p
K
a3
=12.32
pH
锛?/p>
p
K
a
+lg
)
PO
(H
)
(HPO
4
2
2
4
飥?
飥?
n
n
=7.21+lg
mol
010
.
0
mol
030
.
0
=7.68
锛?/p>
2
锛夊姞鍏?/p>
0.005 0 mol HCl
鍚庯細
pH
锛?/p>
p
K
a
+lg
)
PO
(H
)
(HPO
4
2
2
4
飥?
飥?
n
n
=7.21+lg
0.0050mol
0.010mol
0.0050mol
0.030mol
飥?/p>
飥?/p>
= 7.42
渚?/p>
4-2
鏌犳閰革紙缂╁啓
H
3
Cit
锛夊父鐢ㄤ簬閰嶅埗渚涘煿鍏荤粏鑿岀殑缂撳啿婧舵恫銆傚鐢?/p>
500mL
鐨?/p>
0.200
mol路
L
-1
鏌?/p>
妾吀锛岄』鍔犲叆
0.400 mol路
L
-1
鐨?/p>
NaOH
婧舵恫澶氬皯姣崌锛屾墠鑳介厤鎴?/p>
pH
涓?/p>
5.00
鐨勭紦鍐叉憾娑诧紵锛堝凡鐭ユ煚妾吀鐨?/p>
p
Ka
1
=3.14
锛?/p>
p
Ka
2
= 4.77
锛?/p>
p
Ka
3
=6.39
锛?/p>
鏋?/p>
瑕侀厤
pH5.00
鐨勭紦鍐叉憾娑诧紝搴旈�?/p>
p
K
a
2
锛岀紦鍐茬郴
NaH
2
Cit-Na
2
HCit
锛岀敤
NaOH
涓?/p>
H
3
Cit
瀹屽叏鍙嶅簲鐢?/p>
鎴?/p>
NaH
2
Cit
锛屽啀涓?/p>
NaH
2
Cit
閮ㄥ垎鍙嶅簲鐢熸垚
Na
2
HCit
銆?/p>
瑙?/p>
璁?/p>
H
3
Cit
鍏ㄩ儴杞寲涓?/p>
NaH
2
Cit
闇�
NaOH
婧舵恫
V
1
mL
锛?/p>
0.200 mol路
L
-1
脳
500 mL = 0.400 mol路
L
-1
脳
V
1
mL
瑙ｅ緱锛?/p>
V
1
= 250
璁?/p>
NaH
2
Cit
閮ㄥ垎杞寲锛岀粍鎴?/p>
NaH
2
Cit
锛?/p>
Na
2
Hcit
缂撳啿绯伙紝闇�
NaOH
婧舵恫
V
2
mL
锛?/p>
NaH
2
Cit + NaOH
Na
2
HCit + H
2
O
n
锛?/p>
Na
2
HCit
锛?/p>
= 0.400 mol路
L
-1
脳
V
2
mL= 0.400
V
2
mmol
n
锛?/p>
NaH
2
Cit
锛?/p>
= 0.200 mol路
L
-1
脳
500 mL
锛?/p>
0.400 mol路
L
-1
脳
V
2
mL