1)

The conductance  of a 0.0015 M aqueous solution of a weak monobasic acid was determined by using a conductivity cell consisting of platinised pt electrodes.  The distance between the electrodes  is 120 cm with an area of cross section of 1 cm2. The conductance of this solution was found to be 5× 10-7 S. The pH of the solution is 4. The value of limiting molar conductivity ( 0m) of this weak monobasic acid in aqueous solution is Z× 102 S cm-1 mol-1. The value of Z is


A) 600

B) 800

C) 500

D) 400

Answer:

Option A

Explanation:

 pH = C α=104

    α=104.0015

 Also, onductance (G)=  K(AI)

    K=G(IA)=5×107×1201=6×105

     c=k×1000C

  =  6×105×1000.0015

     =cα=6×105×1000.0015×0.0015104

        =600=6 x102  S cm-1 mol-1