Question

What will be standard cell potential of galvanic cell with the following reaction?
$2Cr_{\left(s\right)}+3Cd^{2+}_{\left(aq\right)} \to2Cr^{3+}_{\left(aq\right)}+3Cd_{\left(s\right)}$
[Given : $E^{\circ}_{Cr^{3+}/Cr}=-0.74\,V$ and $E^{\circ}_{Cd^{2+}/Cd}=-0.40\,V$]

• A. $0.74\,V$
• B. $1.14\,V$
• C. $0.34\,V$
• D. $-0.34\,V$

Answer 1

Answer: (C)

$E^{\circ}_{cell}=E^{\circ}_{cathode}-E^{\circ}_{anode}$
$E^{\circ}_{cell}=E^{\circ}_{cd^{2+}/Cd}-E^{\circ}_{Cr^{3+}/Cr}$
$=-0.40-\left(-0.74\right)$
$=+0.34\,V$