Question

A brass plate of surface area 200 cm² on one side is electroplated with 0.10 mm thick silver layers on both sides using a 15 A current. Find the time taken to do the job. The specific gravity of silver is 10.5 and its atomic weight is 107.9 g/mol⁻¹.

Answer 1

Given:-

Current, i = 15 A

Surface area of the plate = 200 cm²,

Thickness of silver deposited= 0.1 mm = 0.01 cm

Volume of Ag deposited on one side = 200 × 0.01 cm³ = 2 cm³

∴ Volume of Ag deposited on both side = 4 cm³
Mass of silver deposited,

m = Volume × Specific gravity × 1000 = 4 × 10^-3 × 10.5 ×1000 = 42 kg

Using the formula, m = Zit, we get:-

42 = Z_Ag × 15 × t

\[\Rightarrow t = \frac{42 \times 96500}{107 . 9 \times 15}  s\]

\[ \Rightarrow t = 2504 . 17  s   =   42\text{ minutes}\]