Electrochemistry 1 Question 31
30. If the cathode is a $\mathrm{Hg}$ electrode, the maximum weight (in gram) of amalgam formed from this solution is
(a) 200
(b) 225
(c) 400
(d) 446
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Answer:
Correct Answer: 30. (d)
Solution:
- At cathode $\mathrm{Na}^{+}+e^{-} \xrightarrow{\mathrm{Hg}} \underset{\text { Amalgam }}{\mathrm{Na}(\mathrm{Hg})}$
Two moles of $\mathrm{Na}$ formed during electrolysis would produce two moles of $\mathrm{Na}(\mathrm{Hg})$ amalgam.
$\Rightarrow$ mass of amalgam $=2 \times(23+200)=446 \mathrm{g}$
