Three electrolytic cells (X), (Y) and (Z) containing solutions of , and respectively are connected…
Three electrolytic cells (X), (Y) and (Z) containing solutions of $\text{AgNO}_3$, $\text{CuSO}_4$ and $\text{ZnSO}_4$ respectively are connected in series. A steady current of $1\cdot5\text{ ampere}$ is passed through these electrolytic cells until $1\cdot45\text{ g}$ of silver is deposited at the cathode of cell (X).
(Atomic weight of $\text{Ag} = 108$, $\text{Cu} = 63\cdot5$ and $\text{Zn} = 65\cdot3$)
(a)
How much of charge is given to the electrolyte solution?
(b)
What mass of copper and zinc is deposited at the respective cathode?
Answer
Answer (a)
AIWritten by AI (gemini) - it can contain mistakes.
Reaction at cathode: $\text{Ag}^+ + e^- \rightarrow \text{Ag}$.
$108\text{ g}$ of $\text{Ag}$ is deposited by $96500\text{ C}$.
Charge $Q = \frac{96500 \times 1\cdot45}{108} = 1295\cdot6\text{ coulombs}$.
Final answer: 1295.6 C
Final answer: 1295.6 C
Answer (b)
AIWritten by AI (gemini) - it can contain mistakes.
From Faraday's second law of electrolysis:
$\frac{\text{Mass of Cu deposited}}{\text{Mass of Ag deposited}} = \frac{E_{\text{Cu}}}{E_{\text{Ag}}} = \frac{63\cdot5 / 2}{108} = \frac{31\cdot75}{108}$
$\text{Mass of Cu} = \frac{1\cdot45 \times 31\cdot75}{108} = 0\cdot426\text{ g}$
$\frac{\text{Mass of Zn deposited}}{\text{Mass of Ag deposited}} = \frac{E_{\text{Zn}}}{E_{\text{Ag}}} = \frac{65\cdot3 / 2}{108} = \frac{32\cdot65}{108}$
$\text{Mass of Zn} = \frac{1\cdot45 \times 32\cdot65}{108} = 0\cdot438\text{ g}$
Final answer: 0.426 g Cu, 0.438 g Zn
Final answer: 0.426, 0.438 g
From ISC 2027 Specimen Chemistry Paper 1, question 17(i).