Resistance of 0.2 M solution of an electrolyte is 5 0  Ω . The specific conductance of the…

Resistance of 0.2 M solution of an electrolyte is 5 0  Ω . The specific conductance of the solution is 1.4 S m -1 . The resistance of 0.5 M solution of the same electrolyte is 28 0  Ω . The molar conductivity of 0.5 M solution of the electrolyte in S m 2 mol -1 is :
  1. 5 × 1 0 - 4
  2. 5 × 1 0 - 3
  3. 5 × 1 0 3
  4. 5 × 1 0 2

Solution

K = 1 R l a

K 0.2 M = 1 5 0 l a      ...... (I)

K 0.5 M = 1 28 0 l a      ...... (II)

K 0.5 M K 0.2 M = 1 2 8 0 × 5 0

K 0.5 M = 1.4 2 8 0 × 5 0 = 1 4

Λ m = K C = 1 4 × 1 0.5 × 1 0 3 = 5 × 1 0 - 4  Ω -1 m 2 mol -1

C = concentration in mol/m 3 = 0.5 × 1 0 3 moles/m 3

Asked in: JEE Main 2014 (06 Apr)

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