Step 1: Using Faraday’s Law of Electrolysis.
The mass of the substance deposited is given by:
\[
m = \frac{E \times I \times t}{96500}
\]
Since the same current flows through both cells,
\[
\frac{m_{{Ag}}}{E_{{Ag}}} = \frac{m_{{Cu}}}{E_{{Cu}}}
\]
where:
- \( m_{{Ag}} = 0.18 \) g, \( E_{{Ag}} = 108 \),
- \( E_{{Cu}} = 63.5 \),
- \( m_{{Cu}} \) is unknown.
Step 2: Solving for \( m_{{Cu}} \).
\[
\frac{0.18}{108} = \frac{m_{{Cu}}}{63.5}
\]
\[
m_{{Cu}} = \frac{0.18 \times 63.5}{108} = 0.0529 { g}
\]