Question

The mass of zinc produced by the electrolysis of zinc sulfate solution with a steady current of 0.015 A for 15 minutes is _____ \( \times \, 10^{-4} \) g.
(Atomic mass of zinc = 65.4 amu)

Answer 1

Correct Answer: 45.75

The reaction for the deposition of zinc is as follows:

Zn²⁺ + 2e^- → Zn

Using the formula for electrolysis:

W = \( \frac{Z \times i \times t}{F} \)

where

• Z = \( \frac{65.4}{2} \) (Equivalent weight of zinc),
• i = 0.015 A (current),
• t = 15 $\times$ 60 seconds,
• F = 96500 C/mol (Faraday constant).

Calculating the mass of zinc:

W = \( \frac{65.4}{2 \times 96500} \times 0.015 \times 15 \times 60 \)

W = 45.75 $\times$ 10^-4 g

Since the answer can be approximated, we also consider 46 $\times$ 10^-4 g.

So, the correct answer is: 45.75 or 46