Question

Standard electrode potential for $S{n}^{4+}|S{n}^{2+}$ couple is $+0.15V$ and that for the $C{r}^{3+}|Cr$ couple is $-0.74V$, these two couples in their standard state are connected to make a cell potential will be:

• A. $+1.19V$
• B. $+0.89V$
• C. $+0.18V$
• D. $+1.83V$

Answer 1

Answer: (B)

$+0.89V$

$E_{S{n}^{4+}/S{n}^{2+}}^0=+0.15V$
$E_{C{r}^{3+}/Cr}^0=-0.74V$
Now,
$E_{cell}^0=E_C^0-E_A^0=0.15-(-0.74)$
$E_{cell}^0=+0.89V$

Option B is correct.