A sample of water from a large swimming pool has a resistance of `10000Omega` at `25^(@)C` when placed in a certain conductace cell. When filled with `0.02M KCI` solution, the cell has a resistance of `100 Omega` at `25^(@)C, 585 gm` of `NaCI` were dissolved in the pool, which was throughly stirred. A sample of this solution gave a resistance of `8000 Omega`. Given: Molar conductance of `NaCI` at that concentration is `125 Omega^(-1) cm^(2) mol^(-1)` and molar conductivity of `KCI` at `0.02 M` is `200W^(-1) cm^(2) mol^(-1)`. Conductivity `(Scm^(-1))` of `H_(2)O` is:A. `4 xx 10^(-2)`B. `4 xx 10^(-3)`C. `4 xx 10^(-5)`D. None of these

A sample of water from a large swimming pool has a resistance of `1000

1.	A sample of water from a large swimming pool has a resistance of `10000Omega` at `25^(@)C` when placed in a certain conductace cell. When filled with `0.02M KCI` solution, the cell has a resistance of `100 Omega` at `25^(@)C, 585 gm` of `NaCI` were dissolved in the pool, which was throughly stirred. A sample of this solution gave a resistance of `8000 Omega`. Given: Molar conductance of `NaCI` at that concentration is `125 Omega^(-1) cm^(2) mol^(-1)` and molar conductivity of `KCI` at `0.02 M` is `200W^(-1) cm^(2) mol^(-1)`. Conductivity `(Scm^(-1))` of `H_(2)O` is:A. `4 xx 10^(-2)`B. `4 xx 10^(-3)`C. `4 xx 10^(-5)`D. None of these
Answer» Correct Answer - C `[NaCI] = (585//58.5)/(V(l))` `k_(NaCIsolution) = (1)/(8000) xx 0.4 = 5 xx 10^(-5)` `^^_(m) =(K(NaCI)xx1000)/((585//58.5)/(V)) =125` `K(NaCI) xx V(l) xx 100 = 125, V(l) = (125)/(100 xx k(NaCI))` `k(H_(2)O) = (1)/(10000) xx 0.4 = 4 xx 10^(-4) = 4 xx 10^(-5)`

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