Verified Solution • 2025–26 Session moderate

QJEEM19Ch83c2: JEE Main 2019 Chemistry - Class 12 JEEM19Ch83c2 Solution: In the cell Pt

In the cell

Pt|(s)|H2(g, 1 bar)|HCl(aq)|AgCl|(s)|Ag(s)|Pt(s)

the cell potential is 0.92 V when a 10–6 molal HCl solution is used. The standard electrode potential of (AgCl/ AgCl– ) electrode is :
{Given,  2.303RTF=0.06V  at  298}

Multiple Choice Options

  • A 0.94 V
  • B 0.40 V
  • C 0.76 V
  • D 0.20 V

Step-by-Step Verified Solution

Anode : H2(g) → 2H+(aq) + 2e-

Cathode : AgCl(s) + e- → Ag(s) + Cl-(aq)
---------------------------------------------------------------
            H2(g) + 2AgCl(s) → 2Ag(s) + 2H+(aq) + 2Cl-(aq)

From Nernst equation we know,

Ecell = E0cell - 0.06nlog⁡Q

Here,

Ecell = E0cell - 0.062log⁡[H+]2[Cl−]2PH2

⇒ 0.92 = E0AgCl/AgCl - - 0.03log⁡[10−6]2[10−6]21

⇒ E0AgCl/AgCl = 0.92 - 0.72 = 0.2 V

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