The resistance of a conductivity cell is measured as 190 Omega using 0.1 K KCl solution (specific conductance of 0.1 M KCl is 1.3 Sm^(-1)). When the same cell is filled with 0.003 M sodium chloride solution, the measured resistance is 6.3 Omega . Both these measurement are made at a particular temperature. Calculate the specificc and molar conductance of NaCl solution.

The resistance of a conductivity cell is measured as 190 Omega using 0

1.	The resistance of a conductivity cell is measured as 190 Omega using 0.1 K KCl solution (specific conductance of 0.1 M KCl is 1.3 Sm^(-1)). When the same cell is filled with 0.003 M sodium chloride solution, the measured resistance is 6.3 Omega . Both these measurement are made at a particular temperature. Calculate the specificc and molar conductance of NaCl solution.
Answer» Solution :GIVEN that `k = 1.3 Sm^(-1)` (for 0.1M KCl solution) `R = 190 Omega` `(l/A) = k.R = (1.3 Sm^(-1))(190 Omega) = 247 m^(-1)` `k_(NACL) = 1/(R_((NaCl))) (l/A) = 1/(6.3 KQ) (247 m^(-1)) "" 6.3K Omega = 6.3 xx 10^(3) Omega` `= 39.2 xx 10^(-3) Sm^(-1)` `Lambda_m = (k xx 10^(-3) mol^1 m^3)/(M) = (39.2 xx 10^(-3)(Sm^(-1)) xx 10^(-3)(mol^(-1)m^3))/(0.003)` `Lambda = 13.04 xx 10^(-3) Sm^(-2) mol^(-1)` .