Question

What will be the standard cell potential of galvanic cell with the following reaction?

$2Cr_{(s)} + 3Cd^{2 +}(aq) \rightarrow 2C{r^{3 +}}_{(aq)} + 3Cd_{(s)}$

[Given

$Eº_{Cr^{3 +}/Cr} = - 0.74V$ and $Eº_{Cd^{3 +}/Cd} = - 0.40V$ ]

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

Answer 1

Answer: (C)

$0.34V$

Answer 2

$Eº_{cell} = Eº_{cathode} - Eº_{anode}$

$Eº_{cell} = Eº_{Cd^{2 +}/Cd} - Eº_{Cr^{3 +}/Cr}$

$= - 0.40 - ( - 0.74) = + 0.34V$