Electrochemistry 1 Question 36
35. How many grams of silver could be plated out on a serving tray by electrolysis of a solution containing silver in +1 oxidation state for a period of $8.0 \mathrm{h}$ at a current of $8.46 \mathrm{A}$ ? What is the area of the tray, if the thickness of the silver plating is $0.00254 \mathrm{cm}$ ? Density of silver is $10.5 \mathrm{g} / \mathrm{cm}^{3}$.
(1997, 3M)
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Answer:
Correct Answer: 35. $3000 \mathrm{cm}^{2}$
Solution:
- Coulombs passed $=8.46 \times 8 \times 60 \times 60=243648 \mathrm{C}$
Number of Faraday’s passed $=\frac{243648}{96500}=2.52$
Weight of $\mathrm{Cu}$ plated $=2.52 \times \frac{63.5}{2} \mathrm{g}=80.01 \mathrm{g}$
Volume of $\mathrm{Cu}$ plated $=\frac{80.01}{10.5}=7.62 \mathrm{cm}^{3}$
$\Rightarrow$ Area plated out $=\frac{7.62}{0.00254}=3000 \mathrm{cm}^{2}$
