Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 20208 JanuaryEvening Shift
Exam
JEE Main
Year
2020
Date
8 January
Shift
Evening Shift
Subject
Chemistry
Chapter
Electrochemistry

JEE Main 2020 · 8 January · Evening Shift · Chemistry · Electrochemistry

For an electrochemical cell Sn(s)| Sn ^ 2 + (aq, 1M)|| Pb ^ 2 +...

For an electrochemical cell Sn(s)∣Sn2+(aq,1M)∣∣Pb2+(aq,1M)∣Pb(s)Sn\left(s\right)\left|{Sn}^{2} + \left(aq, 1M\right)\right|\left|{Pb}^{2 +}\left(aq, 1M\right)\right|Pb\left(s\right) the ratio [Sn2+][Pb2+]\dfrac{\left[{Sn}^{2 +}\right]}{\left[{Pb}^{2 +}\right]} when this cell attains equilibrium is _______
(Given: ESn2+∣Sn0=−0.14V,EPb2+∣Pb0=−0.13V,2.303RTF=0.06{E}_{{Sn}^{2 +}|Sn}^{0} = - 0 .14 V, {E}_{{Pb}^{2 +}|Pb}^{0} = - 0 .13 V, \dfrac{2 .303 RT}{F} = 0 .06)

Correct answer

0

Step-by-step solution

Cell reaction is:

Sn(s)+Pb+2(aq)→Sn+2(aq)+Pb(s)\text{Sn} ( \text{s} ) + {\text{Pb}}^{+ 2} ( \text{aq} ) \to {\text{Sn}}^{+ 2} ( \text{aq} ) + \text{Pb} ( \text{s} )

Apply Nernst equation:

Ecell=Ecell0−0.062log[Sn+2][Pb+2].....(1){\text{E}}_{\text{cell}} = {\text{E}}_{\text{cell}}^{0} - \dfrac{0.06}{2} log\dfrac{\left[{\text{Sn}}^{+ 2}\right]}{\left[{\text{Pb}}^{+ 2}\right]} .....\left(1\right)

Ecell0=−0.13+0.14=0.01V{\text{E}}_{\text{cell}}^{0} = - 0.13 + 0.14 = 0.01\text{V}

At equilibrium : Ecell=0\text{E}\text{cell} = 0 Substituting in (1)

0=0.01−0.062log[Sn+2][Pb+2]0 = 0.01 - \dfrac{0.06}{2} log\dfrac{\left[{\text{Sn}}^{+ 2}\right]}{\left[{\text{Pb}}^{+ 2}\right]}

⇒13=log[Sn+2][Pb+2]⇒ \dfrac{1}{3} = log\dfrac{\left[{\text{Sn}}^{+ 2}\right]}{\left[{\text{Pb}}^{+ 2}\right]}

⇒[Sn+2][Pb+2]=2.15⇒ \dfrac{\left[{\text{Sn}}^{+ 2}\right]}{\left[{\text{Pb}}^{+ 2}\right]} = 2.15
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