4)04907。试计算NH4Cl0012625Sm2mol1,(
mNH4及mCl。
解:离子的无限稀释电导率和电迁移数有以下关系
m,tmm,tm
m
NH
4
(tNH)mNH4Cl4
0490700126256195103Sm2mol11
mCl
(tCl)mNH4Cl
1049070012625643010
1
3
Sm2mol1
或
mmm,,
m2mol1mNH4ClmClmNH400126256195×1036430×103S
7725℃将电导率为014Sm1的KCl溶液装入一电导池中,测得其电阻为525W。在同一电导池中装入01moldm3的NH3H2O溶液,测得电阻为2030W。利用表732中的数据计算NH3H2O的解离度及解离常熟K。
解:查表知NH3H2O无限稀释摩尔电导率为
mNH3H2OmNH4mOH
735×104198×1042715×104Sm2mol1
a
mNH3H2ONH3H2OmNH3H2OcNH3H2OmNH3H2O
KcellGNH3H2OKCl)RKCl)cNH3H2OmNH3H2OcNH3H2ORNH3H2OmNH3H2O
014152501100020302715104001344
fcNHcOH42cc001344201caK1834105cNH3H2O1ac10013441c
78H2O25℃时水的电导率为55×106Sm1,密度为9970kgm2。H2O中存在下列平衡:
HOH,计算此时H2O的摩尔电导率、解离度和H的浓度。已知:mH
34965×104Sm2mol1,104Sm2mol1。mOH1980×
解:mH2O
kH2OkH2OcH2OH2OMH2O
551069931011Sm2mol13997091018
mH2OHOm2mH2OmHmOH
99291011Sm2mol1181310942134965198010Smmol997cHcaH2OMH2Oa18131091004107molmd318
79已知25℃时水的离子积Kw1008×1014,NaOH、HCl和NaCl的m分别等于0024811
Sm2mol1,0042616Sm2mol1和00212545Sm2mol1。(1)求25℃时纯水的电导率;(2)利用该纯水配制AgBr饱和水溶液,测得r