Easy INTEGER +4 / -1 PYQ · JEE Mains 2020

For the disproportionation reaction
2Cu+(aq) ⇌ Cu(s) + Cu2+(aq) at 298 K. ln K
(where K is the equilibrium constant) is
___________ × 10–1.
Given :
($E_{C{u^{2 + }}/C{u^ + }}^0 = 0.16V$
$E_{C{u^ + }/Cu}^0 = 0.52V$
${{RT} \over F} = 0.025$)

Answer (integer) 144

Solution

$E_{cell}^0$ = $E_{C{u^ + }/Cu}^0$ - $E_{C{u^{2 + }}/C{u^ + }}^0$ <br><br>= 0.52 – 0.16 <br><br>= 0.36 V <br><br>At equilibrium, E<sub>cell</sub> = 0 <br><br>$E_{cell}^0$ = ${{RT} \over {nF}}$ln K <br><br>$\Rightarrow$ ln K = ${{E_{cell}^0 \times nF} \over {RT}}$ <br><br>= ${{0.36 \times 1} \over {0.025}}$ = 14.4 = 144 $\times$ 10<sup>-1</sup>

About this question

Subject: Chemistry · Chapter: Electrochemistry · Topic: Electrochemical Cells

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