A current of 9.65 A is drawn from a Daniel cell for exactly 1 hr. The loss in mass at anode and gain in mass at cathode, respectively are |
11.43 g, 11.77 g 11.77 g, 11.43 g 22.86 g, 23.54 g 23.54, 22.86 g |
11.77 g, 11.43 g |
The correct answer is option 2. 11.77 g, 11.43 g. To find the loss in mass at the anode and the gain in mass at the cathode of a Daniel cell, we'll use Faraday's laws of electrolysis. Daniel Cell Reaction In a Daniel cell, the reactions at the electrodes are: Anode Reaction: Zn(s) → Zn²⁺(aq) + 2e⁻ Cathode Reaction: Cu²⁺(aq) + 2e⁻ → Cu(s) The cell reaction is: \(\text{Zn(s)} + \text{Cu}^{2+}(aq) \rightarrow \text{Zn}^{2+}(aq) + \text{Cu(s)}\) Given Data Current (\(I\)) = 9.65 A Time (\(t\)) = 1 hour = 3600 seconds Faraday's constant (\(F\)) = 96500 C/mol (approximately) Total Charge (Q): \( Q = I \times t \) \( Q = 9.65 \text{ A} \times 3600 \text{ s} \) \(Q = 34,740 \text{ C}\) The number of moles of electrons transferred is given by: \(\text{Moles of electrons} = \frac{Q}{F} \) \(\text{Moles of electrons} = \frac{34,740 \text{ C}}{96,500 \text{ C/mol}} \) \(\text{Moles of electrons} \approx 0.36 \text{ mol}\) The molar mass of zinc is 65.38 g/mol. The loss in mass at the anode can be calculated using: \(\text{Mass loss} = \text{Moles of electrons} \times \text{Molar mass of Zn}\) Since 1 mole of Zn releases 2 moles of electrons: \(\text{Moles of Zn} = \frac{0.36 \text{ mol}}{2} \) \(\text{Moles of Zn} = 0.18 \text{ mol}\) \(\text{Mass loss} = 0.18 \text{ mol} \times 65.38 \text{ g/mol}\) \(\text{Mass loss} \approx 11.77 \text{ g}\) The molar mass of copper is 63.55 g/mol. The gain in mass at the cathode can be calculated similarly: \(\text{Mass gain} = \text{Moles of electrons} \times \text{Molar mass of Cu}\) Since 1 mole of Cu²⁺ accepts 2 moles of electrons: \(\text{Moles of Cu} = \frac{0.36 \text{ mol}}{2}\) \(\text{Moles of Cu} = 0.18 \text{ mol}\) \(\text{Mass gain} = 0.18 \text{ mol} \times 63.55 \text{ g/mol}\) \(\text{Mass gain} \approx 11.43 \text{ g} \) Summary Loss in mass at anode (Zinc): 11.77 g Gain in mass at cathode (Copper): 11.43 g Thus, the correct answer is: 11.77 g, 11.43 g. |