Soru
9) Which of the following(s)is/ are correct for the following cell? Cd^+2(0.25M)vert Cd(s)Vert Cu^+2(0.45M)vert Cu(s) (E^aCu^n/Cu=0.337V;E^circ Ca^n/Ca^n-0.403V) I- The cell type is an electrolytic cell II-Cell Voltage is -0.421V III- The Free energy of the reaction is -144.25kJ A) 1 and II B) I and III C II and III D) Only 1 E) Only III
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4.1
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Usta · 5 yıl öğretmeni
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Cevap
To determine which statements are correct for the given cell, we need to analyze the cell notation and the provided standard reduction potentials.The given cell notation is:
The standard reduction potentials are:
Let's break down each statement:I. **The cell type is an electrolytic cell:** - This statement is incorrect. The cell notation indicates it is a galvanic (or voltaic) cell because it involves a spontaneous redox reaction where electrons flow from the anode (Cd) to the cathode (Cu).II. **Cell Voltage is -0.421V:** - To find the cell voltage (E_cell), we use the Nernst equation for each half-reaction and then calculate the overall cell potential. - For the reduction half-reaction (Cu^+2 + 2e^- → Cu):
- For the oxidation half-reaction (Cd → Cd^+2 + 2e^-):
- The overall cell voltage (E_cell) is the difference between the cathode and anode potentials:
- This statement is incorrect because the calculated cell voltage is 0.7545V, not -0.421V.III. **The Free energy of the reaction is -144.25kJ:** - The free energy change (ΔG) can be calculated using the formula:
where
is the number of moles of electrons transferred (2 moles in this case, since each Cd atom loses 2 electrons and each Cu^+2 ion gains 2 electrons).
- This statement is approximately correct, as the calculated free energy change is -145.7 kJ, which is close to -144.25 kJ.Therefore, the correct answer is:E) Only III