The equivalent conductance of `NaCl` at concentration of `C` and at infinite dilution are `lambda_(C)` and `lambda_(oo)` respectively. The correct relationship between `lambda_(C)` and `lambda_(oo)` is given as `:`
`(` where the constant `B` is positive `)`

Options

A. `lamda_(C) = lamda_(oo) - (B)sqrtC`
B. `lamda_(C) = lamda_(oo) + (B)sqrtC`
C. `lamda_(C) = lamda_(oo) + (B)C`
D. `lamda_(C) = lamda_(oo) - (B)C`

Answer

A

Explanation

According to Debyy Huckel's theory, for strong electrolytes, equivalent conductivity inceases slowly with dilution and can be represented by the equation:
`lamda_(C) = lamda_(oo) - (B)sqrt(C)`
If can be seen that if we plot `lamda_(C)` against `sqrt(C)`, we obtain a straight line with intercept equal to `lamda_(oo)` and slope equal a to `-(B)`. The value of the constant `'B'` for a givben solvent and temperature depends on the type of electrolytes the charges on the cation and anion produced on the dissociation of the electrolyte in the solution. All strong electrolytes of a particular type (such as `NaCl, KCl`, etc.) have the same value for `'B'`.