The molar conductivity of `KCl` solution at different concentrations at `298 K` is given below `:`
`{:(c or M (mol L^(-1)),wedge_(m)(Scm^(2)mol^(-1))),(0.000198,148.61),(0.000309,148.29),(0.000521,147.81),(0.000989,147.09):}`
Show that a plot between `wedge_(m)` and `sqrt(c)` is a straight line. Determine the value of `wedge_(m)^(@)` and `A` for `KCl` .

Answer

`Lambda_(m) = 150 .0 S cm^(2) mol^(-1)` and A (slope) = `87.46 S cm^(2) mol^(-1) // (mol L^(-1))^(1/2)`

Explanation

Taking the square root of concentration , we get ,
`{:(C(mol L^(-1)) , C^(1//2) (mol L^(-1))^(1//2) , Lambda_(m) (S cm^(2) mol^(-1))) , (0.000198 , 0.01407 , 148.61), (0.000309 , 0.01758 , 148.29) , (0.00521 , 0.02283 , 147.81) , (0.000989 , 0.03145 , 147.09):}`
Plot of `Lambda_(m)` and `C^(1//2)` is given below :

The extrapolation of the straight line to zero concentration (intercept) gives the value of `Lambda_(m)^(@) = 150.0 S cm^(2) mol^(-1)`
A = -slope = 87.46 ` S cm^(2) mol^(-1) // (mol L^(-1) )^(1//2`