JEE Main · 2025 · 03 Apr 2025 · Shift 1 · Redox Reactions and Electrochemistry

Correct order of limiting molar conductivity for cations in water at 298 K is :

Answer: (B)

Solution

Limiting molar conductivity grows with ionic charge and with smaller hydrated size, and

H^{+}

is exceptional through its Grotthuss proton-hopping. The values (in

S cm^{2} mol^{- 1}

) are roughly

H^{+} 350

Ca^{2 +} 119

Mg^{2 +} 106

K^{+} 74

and

Na^{+} 50

. The order of limiting molar conductivity is

H^{+} > Ca^{2 +} > Mg^{2 +} > K^{+} > Na^{+}

JEE Main · 2025 · 03 Apr 2025 · Shift 1 · Single correct option