JEE Advanced2015ChemistryElectrochemistryActual
The molar conductivity of a solution of a weak acid HX (0.01 M) is 10 times smaller than the molar conductivity of a solution of a weak acid HY (0.10 M). If λ X - 0 ≈ λ Y - 0 , the difference in their p K a values, p K a H X - p K a ( H Y ) , is (Consider degree of ionization of both acids to << 1)
Correct answer
3
Step-by-step solution
λ X - 0 ≈ λ Y - 0 ⇒ λ H + 0 + λ X - 0   ≈ λ H + 0 + λ Y - 0 ⇒ λ H X 0 ≈ λ H Y 0 ...... (i) Also, λ m λ m 0 = α , So λ m H X =   λ m 0 α 1 and λ m H Y =   λ m 0 α 2 (Where α 1 and α 2 are degree of dissociation of HX and HY respectively) Now, given that λ m H Y = 10 λ m H X ⇒ λ m 0 α 2 = 10 × λ m 0 α 1 α 2 = 10 α 1 ...... (ii) K