Cell Potential and Free Energy - AP Chemistry
Card 1 of 30
Calculate the cell potential given $E^0_\text{cell} = 1.10 \text{ V}$ and $Q = 1.0$ at $298 \text{ K}$.
Calculate the cell potential given $E^0_\text{cell} = 1.10 \text{ V}$ and $Q = 1.0$ at $298 \text{ K}$.
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$E = E^0_\text{cell} = 1.10 \text{ V}$. When $Q = 1$, the Nernst equation reduces to $E = E^0$.
$E = E^0_\text{cell} = 1.10 \text{ V}$. When $Q = 1$, the Nernst equation reduces to $E = E^0$.
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Identify the temperature used for standard conditions in electrochemistry.
Identify the temperature used for standard conditions in electrochemistry.
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$298 \text{ K}$. Standard temperature for electrochemical measurements (25°C).
$298 \text{ K}$. Standard temperature for electrochemical measurements (25°C).
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What is the role of the salt bridge in a galvanic cell?
What is the role of the salt bridge in a galvanic cell?
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To maintain electrical neutrality. Allows ion migration to balance charge buildup at electrodes.
To maintain electrical neutrality. Allows ion migration to balance charge buildup at electrodes.
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Why is the standard hydrogen electrode used as a reference?
Why is the standard hydrogen electrode used as a reference?
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Assigned a potential of 0.00 V. Provides a universal standard for comparing electrode potentials.
Assigned a potential of 0.00 V. Provides a universal standard for comparing electrode potentials.
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What is Faraday's constant value?
What is Faraday's constant value?
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$96485 \text{ C/mol}$. Conversion factor between moles of electrons and electric charge.
$96485 \text{ C/mol}$. Conversion factor between moles of electrons and electric charge.
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Calculate $\triangle G$ for a cell with $n=2$, $F=96485 \text{ C/mol}$, and $E=1.5 \text{ V}$.
Calculate $\triangle G$ for a cell with $n=2$, $F=96485 \text{ C/mol}$, and $E=1.5 \text{ V}$.
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$\triangle G = -289455 \text{ J/mol}$. Using $\triangle G = -nFE$ with given values: $-(2)(96485)(1.5)$.
$\triangle G = -289455 \text{ J/mol}$. Using $\triangle G = -nFE$ with given values: $-(2)(96485)(1.5)$.
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What is the standard cell potential for a galvanic cell?
What is the standard cell potential for a galvanic cell?
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The cell potential under standard conditions. Measured when all species are at standard conditions (1 M, 1 atm, 25°C).
The cell potential under standard conditions. Measured when all species are at standard conditions (1 M, 1 atm, 25°C).
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What is the equation for standard free energy change, $\triangle G^0$?
What is the equation for standard free energy change, $\triangle G^0$?
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$\triangle G^0 = -nFE^0_\text{cell}$. Standard free energy relates to standard cell potential through Faraday's constant.
$\triangle G^0 = -nFE^0_\text{cell}$. Standard free energy relates to standard cell potential through Faraday's constant.
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Identify the relationship between free energy and cell potential.
Identify the relationship between free energy and cell potential.
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$\Delta G = -nFE$. Shows Gibbs free energy is proportional to cell potential times electrons and Faraday's constant.
$\Delta G = -nFE$. Shows Gibbs free energy is proportional to cell potential times electrons and Faraday's constant.
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What is the standard reduction potential of a hydrogen electrode?
What is the standard reduction potential of a hydrogen electrode?
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0.00 V. Serves as the reference point for measuring all other electrode potentials.
0.00 V. Serves as the reference point for measuring all other electrode potentials.
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State the unit of cell potential.
State the unit of cell potential.
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Volts (V). Standard SI unit for electric potential difference.
Volts (V). Standard SI unit for electric potential difference.
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Determine the spontaneity: $E^0_\text{cell} = -0.76 \text{ V}$.
Determine the spontaneity: $E^0_\text{cell} = -0.76 \text{ V}$.
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Non-spontaneous reaction. Negative standard cell potential indicates $\triangle G^0 > 0$, non-spontaneous.
Non-spontaneous reaction. Negative standard cell potential indicates $\triangle G^0 > 0$, non-spontaneous.
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What is the effect of increasing reactant concentration on cell potential?
What is the effect of increasing reactant concentration on cell potential?
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Increases cell potential. Higher reactant concentration makes $Q$ smaller, increasing $E$.
Increases cell potential. Higher reactant concentration makes $Q$ smaller, increasing $E$.
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State the condition under which $E^0_\text{cell} = 0$.
State the condition under which $E^0_\text{cell} = 0$.
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Equilibrium is established. Zero cell potential means no driving force for electron flow.
Equilibrium is established. Zero cell potential means no driving force for electron flow.
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Calculate $E$ for $E^0_\text{cell} = 1.10 \text{ V}$, $T = 298 \text{ K}$, $n=2$, $Q=0.1$.
Calculate $E$ for $E^0_\text{cell} = 1.10 \text{ V}$, $T = 298 \text{ K}$, $n=2$, $Q=0.1$.
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$E > 1.10 \text{ V}$. When $Q < 1$, the Nernst equation predicts $E > E^0$.
$E > 1.10 \text{ V}$. When $Q < 1$, the Nernst equation predicts $E > E^0$.
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State the relationship between $K_{eq}$ and $E^0_\text{cell}$.
State the relationship between $K_{eq}$ and $E^0_\text{cell}$.
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$E^0_\text{cell} = \frac{RT}{nF} \times \ln K_{eq}$. Equilibrium constant relates to standard cell potential through thermodynamics.
$E^0_\text{cell} = \frac{RT}{nF} \times \ln K_{eq}$. Equilibrium constant relates to standard cell potential through thermodynamics.
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What does a zero cell potential mean in a galvanic cell?
What does a zero cell potential mean in a galvanic cell?
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The cell is at equilibrium. No potential difference means equilibrium between electrodes.
The cell is at equilibrium. No potential difference means equilibrium between electrodes.
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What does a negative $\triangle G$ indicate about a reaction?
What does a negative $\triangle G$ indicate about a reaction?
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The reaction is spontaneous. Negative free energy change indicates thermodynamically favorable process.
The reaction is spontaneous. Negative free energy change indicates thermodynamically favorable process.
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What is the primary purpose of the Nernst equation?
What is the primary purpose of the Nernst equation?
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To calculate cell potential under non-standard conditions. Adjusts standard cell potential for actual concentration and temperature conditions.
To calculate cell potential under non-standard conditions. Adjusts standard cell potential for actual concentration and temperature conditions.
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Calculate the cell potential given $E^0_\text{cell} = 1.10 \text{ V}$ and $Q = 1.0$ at $298 \text{ K}$.
Calculate the cell potential given $E^0_\text{cell} = 1.10 \text{ V}$ and $Q = 1.0$ at $298 \text{ K}$.
Tap to reveal answer
$E = E^0_\text{cell} = 1.10 \text{ V}$. When $Q = 1$, the Nernst equation reduces to $E = E^0$.
$E = E^0_\text{cell} = 1.10 \text{ V}$. When $Q = 1$, the Nernst equation reduces to $E = E^0$.
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Identify the temperature used for standard conditions in electrochemistry.
Identify the temperature used for standard conditions in electrochemistry.
Tap to reveal answer
$298 \text{ K}$. Standard temperature for electrochemical measurements (25°C).
$298 \text{ K}$. Standard temperature for electrochemical measurements (25°C).
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What is the role of the salt bridge in a galvanic cell?
What is the role of the salt bridge in a galvanic cell?
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To maintain electrical neutrality. Allows ion migration to balance charge buildup at electrodes.
To maintain electrical neutrality. Allows ion migration to balance charge buildup at electrodes.
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Why is the standard hydrogen electrode used as a reference?
Why is the standard hydrogen electrode used as a reference?
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Assigned a potential of 0.00 V. Provides a universal standard for comparing electrode potentials.
Assigned a potential of 0.00 V. Provides a universal standard for comparing electrode potentials.
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What is Faraday's constant value?
What is Faraday's constant value?
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$96485 \text{ C/mol}$. Conversion factor between moles of electrons and electric charge.
$96485 \text{ C/mol}$. Conversion factor between moles of electrons and electric charge.
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Calculate $\triangle G$ for a cell with $n=2$, $F=96485 \text{ C/mol}$, and $E=1.5 \text{ V}$.
Calculate $\triangle G$ for a cell with $n=2$, $F=96485 \text{ C/mol}$, and $E=1.5 \text{ V}$.
Tap to reveal answer
$\triangle G = -289455 \text{ J/mol}$. Using $\triangle G = -nFE$ with given values: $-(2)(96485)(1.5)$.
$\triangle G = -289455 \text{ J/mol}$. Using $\triangle G = -nFE$ with given values: $-(2)(96485)(1.5)$.
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Identify the relationship between free energy and cell potential.
Identify the relationship between free energy and cell potential.
Tap to reveal answer
$\triangle G = -nFE$. Shows Gibbs free energy is proportional to cell potential times electrons and Faraday's constant.
$\triangle G = -nFE$. Shows Gibbs free energy is proportional to cell potential times electrons and Faraday's constant.
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What is the standard reduction potential of a hydrogen electrode?
What is the standard reduction potential of a hydrogen electrode?
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0.00 V. Serves as the reference point for measuring all other electrode potentials.
0.00 V. Serves as the reference point for measuring all other electrode potentials.
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What is the standard cell potential for a galvanic cell?
What is the standard cell potential for a galvanic cell?
Tap to reveal answer
The cell potential under standard conditions. Measured when all species are at standard conditions (1 M, 1 atm, 25°C).
The cell potential under standard conditions. Measured when all species are at standard conditions (1 M, 1 atm, 25°C).
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What is the equation for standard free energy change, $\triangle G^0$?
What is the equation for standard free energy change, $\triangle G^0$?
Tap to reveal answer
$\triangle G^0 = -nFE^0_\text{cell}$. Standard free energy relates to standard cell potential through Faraday's constant.
$\triangle G^0 = -nFE^0_\text{cell}$. Standard free energy relates to standard cell potential through Faraday's constant.
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What is the direction of electron flow in a galvanic cell?
What is the direction of electron flow in a galvanic cell?
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From anode to cathode. Electrons move from negative anode to positive cathode through external circuit.
From anode to cathode. Electrons move from negative anode to positive cathode through external circuit.
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