Electrochemistry - Result Question 49
####48. How long a current of $3 A$ has to be passed through a solution of silver nitrate to coat a metal surface of $80 cm^{2}$ with a $0.005 mm$ thick layer?
Density of silver is $10.5 g / cm^{3}$.
$(1985,3 M)$
Show Answer
Answer:
Correct Answer: 48. $(125 s)$
Solution:
- Volume of Ag coating $=80 cm^{2} \times \frac{0.005}{10} cm=0.04 cm^{3}$
$\Rightarrow$ mass of Ag coating $=0.04 \times 10.5 g=0.42 g$
$\Rightarrow$ gram equivalent of $Ag=\frac{0.42}{108}=$ number of Faraday’s
$\Rightarrow \quad \frac{0.42}{108} \times 96500 C=3 \times t \Rightarrow t=125 s$
