无限稀释摩尔电导率Molarconductanceatinfinitedilutionisthe.PPT

Conductometry (电导法) Conductometric Analysis Fundamentals of conductometry Conductivity measurements Analytical applications of conductometric measurements Conductometric Analysis Electrolyte solutions behave as an electrically conductive medium. The change of electrolyte conductivity can indicate the change of the concentration of the total ions, this method is defined as conductometric Analysis 电解质溶液能导电，当溶液中离子浓度发生变化时，其电导也随之改变。用电导来指示溶液中离子浓度的方法称为电导分析法。 摩尔电导率(?m) 3. Factors which influence conductance measurement b. Determination of the total concentration of strong electrolyte solutions salinity of soil and sea water c. Determination of gaseous environmental contaminant in air eg. SO3 NO2, acidic rain determine the change of conductivity after absorption * 1.conductance(G) 、specific conductance (?) 、molar conductance(?m) 电导G：The resistance reciprocal is called conductance, its unit is Siemens G =1/R where 1S=1?-1 Principles- basic property of electrolyte solution 电导率? : The resistivity reciprocal is specific conductance or electrolytic conductivity ? = G ? L / A its unit ：S ? cm-1 两电极板为单位面积，距离为单位长度时溶液的电导。 电导池常数θ：θ = L / A (A the surface area of electrodes; L the distance between electrodes) 由标准KCl溶液的电导率(查表)确定电导率和电导池常数 Ratio L/A is an intrinsic parameter of each conductometric container and is called resistive capacity of conductometric container θ θ = L / A Because specific conductance depends on concentration we introduce the term molar conductance ?m 不同浓度、不同类型电解质导电能力的比较。 距离为单位长度的两电极板间含有单位物质的量的电解质的溶液的电导。 Units：S? cm2? mol-1 Total conductance of the solution is directly proportional to the sum of the n individual ion contributions G = ?ci?m,i 无限稀释摩尔电导率 Molar conductance at infinite dilution is the characteristic constant for given electrolyte 2. Conductance of ions离子的电导 ions ?104 K+ 73.52 Na+