For a closed circuit Daniell cell, which of the following plots is the accurate one at a given temperature ?
Show Hint
Be careful to distinguish between \( E_{cell} \) and \( E_{cell}^{\circ} \). Standard values are constants for a fixed temperature and reaction, much like an equilibrium constant \( K_{eq} \).
The Daniell cell is a type of galvanic cell that converts chemical energy into electrical energy. For a galvanic cell like the Daniell cell, the cell potential (E_{\text{cell}}^{\circ}) remains constant over time as long as the concentrations of reactants and products are maintained at standard conditions. Therefore, the correct plot for a closed circuit Daniell cell at a given temperature is a horizontal line depicting that E_{\text{cell}}^{\circ} remains unchanged over time.
Let's analyze the given options:
Option A shows an increasing line, which is incorrect because E_{\text{cell}}^{\circ} does not increase over time.
Option B shows a horizontal line, which is correct as it represents a constant cell potential.
Option C shows a decreasing line, which is incorrect as the standard cell potential should not decrease for a well-functioning Daniell cell.
Option D shows a downward vertical line, which is incorrect as it doesn't represent the constant nature of cell potential over time.
Thus, the accurate plot for the Daniell cell at a constant temperature is Option B.
