Question

If $x$ is the ratio of currents it takes to produce 4.5 g of platinum from molten $PtC{l}_3$ and $PtC{l}_5$, then $10x$ is__________.
Electrolysis in each case is carried out for 1 min 40 s. (Atomic Mass of Pt = 195.0).

Answer 1

t=1 min. 40 sec. = 100sec.
$PtC{l}_3+3e^{-}\to Pt+3C{l}^{\ominus }$

3 F = 1 mol Pt

$\frac{4.5}{195}molPt=3\times \frac{4.5}{195}F$

$\Rightarrow \frac{I_1\times t}{96500}=3\times \frac{4.5}{195}$

$\Rightarrow I_1=\frac{3\times 4.5\times 96500}{100\times 195}=66.8A$

$PtC{l}_5+5e^{-}\to Pt+5C{l}^{\ominus }$

5 F = 1 mol Pt

$\frac{4.5}{195}molpt=5\times \frac{4.5}{195}F$

$\Rightarrow \frac{I_2\times 100}{96500}=5\times \frac{4.5}{195}$

$\Rightarrow I_2=111.34A$

$x=\frac{I_1}{I_2}\approx 0.6$
$10x=6$
Ans-$6$