Regarding the variation of molar conductivity Lambda_m and conductivity kappa with concentration, the correct statement(s) is/are

For CH3COOH, Lambda_m increases on dilution mainly because its degree of dissociation increases

For both KCl and CH3COOH, kappa decreases on dilution

For KCl, a plot of Lambda_m against sqrtc is nearly linear at low concentration and its intercept at c = 0 gives Lambda deg_m

For KCl, Lambda_m increases on dilution because the number of ions produced per mole of KCl increases

For CH3COOH, Lambda_m increases on dilution mainly because its degree of dissociation increases

For both KCl and CH3COOH, kappa decreases on dilution

For KCl, a plot of Lambda_m against sqrtc is nearly linear at low concentration and its intercept at c = 0 gives Lambda deg_m

JEE Advanced levelOne or more correct optionsDifficulty 2 of 3ec187

Regarding the variation of molar conductivity $Λ_{m}$ and conductivity $κ$ with concentration, the correct statement(s) is/are

AFor KCl, $Λ_{m}$ increases on dilution because the number of ions produced per mole of KCl increases
BFor $CH X_{3} COOH$ , $Λ_{m}$ increases on dilution mainly because its degree of dissociation increases
CFor both KCl and $CH X_{3} COOH$ , $κ$ decreases on dilution
DFor KCl, a plot of $Λ_{m}$ against $c$ is nearly linear at low concentration and its intercept at $c = 0$ gives $Λ_{m}^{\circ}$

KCl is fully dissociated at all concentrations, so the number of ions per mole does not change; its

Λ_{m}

rises on dilution because interionic attractions weaken and ionic mobility increases. Hence (A) is wrong. For a weak acid the increase of

α

on dilution is the main cause of the rise in

Λ_{m}

, so (B) is correct.

κ

counts ions per unit volume and always falls on dilution, so (C) is correct. For a strong electrolyte

Λ_{m} = Λ_{m}^{\circ} - A c

holds at low concentration (Debye-Huckel-Onsager), so the plot is linear and extrapolates to

Λ_{m}^{\circ}

; (D) is correct.