Question

An electroplating unit plates 3.0 g of silver on a brass plate in 3.0 minutes. Find the current used by the unit. The electrochemical equivalent of silver is 1.12 × 10⁻⁶ kg C⁻¹.

Answer 1

Given:-

Mass of silver deposited, m = 3 g

Time taken, t = 3 min. = 180 s

E.C.E. of silver, Z = 1.12 × 10⁻⁶ kg C⁻¹

Using the formula, m = Zit, we get:-

\[3 \times  {10}^{- 3}  = 1 . 12 \times  {10}^{- 6}  \times i \times 180\]

\[\Rightarrow i = \frac{3 \times {10}^{- 3}}{1 . 12 \times {10}^{- 6} \times 180}\]

\[ \Rightarrow i = \frac{1}{6 . 72} \times  {10}^2 \]

\[ \Rightarrow i = 14 . 89 \approx 15  A\]