Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app

JEE Main 20253 AprilMorning Shift

Exam: JEE Main
Year: 2025
Date: 3 April
Shift: Morning Shift
Subject: Chemistry
Chapter: Electrochemistry

JEE Main 2025 · 3 April · Morning Shift · Chemistry · Electrochemistry

Correct order of limiting molar conductivity for cations in water...

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

Options

A $\mathrm{H}^{+} \gt \mathrm{Na}^{+} \gt \mathrm{K}^{+} \gt \mathrm{Ca}^{2+} \gt \mathrm{Mg}^{2+}$
B $\mathrm{H}^{+} \gt \mathrm{Ca}^{2+} \gt \mathrm{Mg}^{2+} \gt \mathrm{K}^{+} \gt \mathrm{Na}^{+}$
C $\mathrm{Mg}^{2+} \gt \mathrm{H}^{+} \gt \mathrm{Ca}^{2+} \gt \mathrm{K}^{+} \gt \mathrm{Na}^{+}$
D $\mathrm{H}^{+} \gt \mathrm{Na}^{+} \gt \mathrm{Ca}^{2+} \gt \mathrm{Mg}^{2+} \gt \mathrm{K}^{+}$

Correct answer

B. $\mathrm{H}^{+} \gt \mathrm{Ca}^{2+} \gt \mathrm{Mg}^{2+} \gt \mathrm{K}^{+} \gt \mathrm{Na}^{+}$

Step-by-step solution

Limiting Molar Conductivities of Ions:
-

\stackrel{\oplus}{\mathrm{H}}: 349.8 \mathrm{Scm}^2 \mathrm{~mol}^{-1}

-

\mathrm{Na}^{+}: 50.11 \mathrm{Scm}^2 \mathrm{~mol}^{-1}

-

\mathrm{K}^{+}: 73.52 \mathrm{Scm}^2 \mathrm{~mol}^{-1}

-

\mathrm{Ca}^{+2}: 119 \mathrm{Scm}^2 \mathrm{~mol}^{-1}

-

\mathrm{Mg}^{+2}: 106.12 \mathrm{Scm}^2 \mathrm{~mol}^{-1}

Therefore correct order of limiting molar conductivity of cations will be -

\stackrel{\oplus}{\mathrm{H}} \gt \mathrm{Ca}^{+2} \gt \mathrm{Mg}^{+2} \gt \mathrm{K}^{+} \gt \mathrm{Na}^{+}

Practice Electrochemistry on Quantrex Academy →

More from Electrochemistry

At 300 K, the molar conductivities of the aqueous solutions of three salts at two… JEE Advanced 2026 Given at 298 K: E^ _ Fe^ 2+ /Fe = X Volt; E^ _ Fe^ 3+ /Fe = Y Volt. The E^ _ Fe^ 3+ /Fe^… JEE Main 2026 For a general redox reaction Anode : Red_1 arrow Ox_1^ n_1^+ + n_1 e^- Cathode : Ox_2 +… JEE Main 2026 Consider the following data. Electrolyte Λ^ ∘ _m (S cm ^2 mol ^ -1 ) BaCl_2 x_1 H_2SO_4… JEE Main 2026 One half cell in a voltaic cell is constructed by dipping silver rod in AgNO_3 solution… JEE Main 2026 At 298 K , the molar conductivity of x\% (w/w) MX solution (aqueous) is 123.5 S cm^2 mol^… JEE Main 2026 An electrochemical cell, consist of the following two redox couples, M^ x+ (aq)/M(s) [E_… JEE Main 2026 Consider the following two half-cell reactions along with the standard reduction… JEE Main 2026 Full Electrochemistry list All JEE Main PYQs