Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 20244 AprilMorning Shift
Exam
JEE Main
Year
2024
Date
4 April
Shift
Morning Shift
Subject
Chemistry
Chapter
Electrochemistry

JEE Main 2024 · 4 April · Morning Shift · Chemistry · Electrochemistry

What pressure (bar) of (H_2) would be required to make emf of...

What pressure (bar) of (\mathrm{H}_2) would be required to make emf of hydrogen electrode zero in pure water at (25^{\circ} \mathrm{C}) ?

Options

  1. A10−710^{-7}
  2. B0.5
  3. C1
  4. D10−1410^{-14}

Correct answer

D. 10−1410^{-14}

Step-by-step solution

2e−+2H+(aq)→H2(g)E=E∘−0.059nlog⁡PH2[H+]20=0−0.0592log⁡PH2(10−7)2log⁡PH2(10−7)2=0PH210−14=1PH2=10−14 bar \begin{aligned} & 2 \mathrm{e}^{-}+2 \mathrm{H}^{+}(\mathrm{aq}) \rightarrow \mathrm{H}_2(\mathrm{ g}) \\ & \mathrm{E}=\mathrm{E}^{\circ}-\frac{0.059}{\mathrm{n}} \log \frac{\mathrm{P}_{\mathrm{H}_2}}{\left[\mathrm{H}^{+}\right]^2} \\ & 0=0-\frac{0.059}{2} \log \frac{\mathrm{P}_{\mathrm{H}_2}}{\left(10^{-7}\right)^2} \\ & \log \frac{\mathrm{P}_{\mathrm{H}_2}}{\left(10^{-7}\right)^2}=0 \\ & \frac{\mathrm{P}_{\mathrm{H}_2}}{10^{-14}}=1 \\ & \mathrm{P}_{\mathrm{H}_2}=10^{-14} \text{ bar }\end{aligned}
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 2026Given at 298 K: E^ _ Fe^ 2+ /Fe = X Volt; E^ _ Fe^ 3+ /Fe = Y Volt. The E^ _ Fe^ 3+ /Fe^… JEE Main 2026For a general redox reaction Anode : Red_1 arrow Ox_1^ n_1^+ + n_1 e^- Cathode : Ox_2 +… JEE Main 2026Consider the following data. Electrolyte Λ^ ∘ _m (S cm ^2 mol ^ -1 ) BaCl_2 x_1 H_2SO_4… JEE Main 2026One half cell in a voltaic cell is constructed by dipping silver rod in AgNO_3 solution… JEE Main 2026At 298 K , the molar conductivity of x\% (w/w) MX solution (aqueous) is 123.5 S cm^2 mol^… JEE Main 2026An electrochemical cell, consist of the following two redox couples, M^ x+ (aq)/M(s) [E_… JEE Main 2026Consider the following two half-cell reactions along with the standard reduction… JEE Main 2026 Full Electrochemistry list All JEE Main PYQs