8 7.4 Activity and activity coefficient 3. Influential factors 4)ionic strength 3)Valence types and concentration In 1921. Lewis. who noted that the type electrolyte 0.1 m 0.2 m 1.0 m nonideality observed in electrolytic RbNO3 0.734 0.658 0.430 solutions primarily stems from the total NHCIO 0.7300.6600.482 concentration of charges present rather than from the chemical nature of the Bacl2 0.50804500.401 Individual ionic species, Introduced 1:2 CaCI 0.510 0.457 0.419 ionic strength 0.3140.2740.342 1:3 FeCl30.3250.2800.270 4z8 ar3) Valence types and concentration 3. Influential factors =  i mi Zi I 2 2 1 type electrolyte 0.1 m 0.2 m 1.0 m 1:1 RbNO3 0.734 0.658 0.430 NH4ClO4 0.730 0.660 0.482 1:2 BaCl2 0.508 0.450 0.401 CaCl2 0.510 0.457 0.419 1:3 LaCl3 0.314 0.274 0.342 FeCl3 0.325 0.280 0.270 In 1921, Lewis, who noted that the nonideality observed in electrolytic solutions primarily stems from the total concentration of charges present rather than from the chemical nature of the individual ionic species, introduced ionic strength. 4) ionic strength §7.4 Activity and activity coefficient 2 0 1 2 4 r q q F  r  =