Gen Chem II Electrochemistry Galvanic Cells
41 flashcards covering Gen Chem II Electrochemistry Galvanic Cells for the GENERAL-CHEMISTRY-2 Gen Chem II Topics section.
Electrochemistry, particularly the study of galvanic cells, is a key topic in General Chemistry II, as outlined by the American Chemical Society's guidelines for undergraduate chemistry education. This area focuses on the conversion of chemical energy into electrical energy through spontaneous redox reactions, which is fundamental for understanding batteries and electrochemical cells.
On practice exams and competency assessments, questions about galvanic cells often involve calculating cell potential, determining the direction of electron flow, or identifying the anode and cathode. A common pitfall is confusing the roles of the anode and cathode; remember that oxidation occurs at the anode and reduction occurs at the cathode. Additionally, questions may present scenarios requiring the application of the Nernst equation, where misapplying the formula can lead to incorrect conclusions.
A practical tip to keep in mind is to always double-check your half-reaction assignments, as small mistakes in identifying oxidation states can lead to larger errors in calculations.
Terms (41)
- 01
What is a galvanic cell?
A galvanic cell is an electrochemical cell that converts chemical energy into electrical energy through spontaneous redox reactions. It consists of two half-cells connected by a salt bridge or porous membrane (Zumdahl, Electrochemistry chapter).
- 02
What is the function of the salt bridge in a galvanic cell?
The salt bridge allows the flow of ions between the two half-cells, maintaining electrical neutrality by balancing the charge as electrons flow through the external circuit (Tro, Electrochemistry chapter).
- 03
What are the components of a galvanic cell?
A galvanic cell typically consists of two electrodes (anode and cathode), two half-cells, an electrolyte solution, and a salt bridge (Brown LeMay, Electrochemistry chapter).
- 04
What is the anode in a galvanic cell?
The anode is the electrode where oxidation occurs, and it is the source of electrons that flow through the external circuit (Zumdahl, Electrochemistry chapter).
- 05
What is the cathode in a galvanic cell?
The cathode is the electrode where reduction occurs, and it is the site where electrons are gained (Tro, Electrochemistry chapter).
- 06
How is the standard cell potential calculated?
The standard cell potential (E°cell) is calculated using the standard reduction potentials of the two half-reactions: E°cell = E°cathode - E°anode (Brown LeMay, Electrochemistry chapter).
- 07
What is the significance of a positive cell potential?
A positive cell potential indicates that the galvanic cell can perform work and that the reaction is spontaneous under standard conditions (Zumdahl, Electrochemistry chapter).
- 08
What happens at the anode during a galvanic cell reaction?
At the anode, oxidation occurs, resulting in the loss of electrons from the oxidized species (Tro, Electrochemistry chapter).
- 09
What happens at the cathode during a galvanic cell reaction?
At the cathode, reduction occurs, where the species gains electrons (Brown LeMay, Electrochemistry chapter).
- 10
What is the role of the electrolyte in a galvanic cell?
The electrolyte facilitates the movement of ions within the half-cells, allowing the redox reaction to proceed (Zumdahl, Electrochemistry chapter).
- 11
How do you determine the direction of electron flow in a galvanic cell?
Electrons flow from the anode to the cathode, following the path of decreasing potential energy (Tro, Electrochemistry chapter).
- 12
What is the Nernst equation used for?
The Nernst equation is used to calculate the cell potential at non-standard conditions, taking into account the concentrations of the reactants and products (Brown LeMay, Electrochemistry chapter).
- 13
What is the relationship between Gibbs free energy and cell potential?
The relationship is given by the equation ΔG = -nFE°cell, where ΔG is the Gibbs free energy change, n is the number of moles of electrons, F is Faraday's constant, and E°cell is the cell potential (Zumdahl, Electrochemistry chapter).
- 14
What does a negative Gibbs free energy indicate about a galvanic cell?
A negative Gibbs free energy indicates that the reaction is spontaneous and can perform work (Tro, Electrochemistry chapter).
- 15
How can the concentration of reactants affect the cell potential?
Changes in the concentration of reactants or products can shift the cell potential according to the Nernst equation, affecting the spontaneity of the reaction (Brown LeMay, Electrochemistry chapter).
- 16
What is the purpose of a voltmeter in a galvanic cell setup?
A voltmeter measures the potential difference (voltage) between the two electrodes in a galvanic cell, indicating the cell's ability to do work (Zumdahl, Electrochemistry chapter).
- 17
What is the electrochemical series?
The electrochemical series is a list of standard reduction potentials for various half-reactions, which helps predict the direction of redox reactions (Tro, Electrochemistry chapter).
- 18
What is a concentration cell?
A concentration cell is a type of galvanic cell where both electrodes are made of the same material but are immersed in solutions of different concentrations (Brown LeMay, Electrochemistry chapter).
- 19
How does temperature affect the cell potential?
Temperature changes can affect the cell potential by influencing the reaction kinetics and the equilibrium position, as described by the Nernst equation (Zumdahl, Electrochemistry chapter).
- 20
What is the role of a primary battery?
A primary battery is a type of galvanic cell that is designed to be used until the reactants are exhausted and cannot be recharged (Tro, Electrochemistry chapter).
- 21
What is the difference between a galvanic cell and an electrolytic cell?
A galvanic cell generates electrical energy from spontaneous chemical reactions, while an electrolytic cell uses electrical energy to drive non-spontaneous reactions (Brown LeMay, Electrochemistry chapter).
- 22
What is the Faraday's law of electrolysis?
Faraday's law states that the amount of substance produced at an electrode during electrolysis is directly proportional to the amount of electric charge passed through the cell (Zumdahl, Electrochemistry chapter).
- 23
What is meant by the term 'redox reaction'?
A redox reaction involves the transfer of electrons between two species, where one is oxidized (loses electrons) and the other is reduced (gains electrons) (Tro, Electrochemistry chapter).
- 24
What is the purpose of a secondary battery?
A secondary battery is designed to be rechargeable, allowing the chemical reactions to be reversed by applying an external electrical current (Brown LeMay, Electrochemistry chapter).
- 25
What does the term 'oxidation state' refer to?
The oxidation state refers to the hypothetical charge that an atom would have if all bonds to atoms of different elements were completely ionic (Zumdahl, Electrochemistry chapter).
- 26
What is the significance of the standard hydrogen electrode?
The standard hydrogen electrode is used as a reference electrode with a defined potential of 0.00 V for measuring the standard reduction potentials of other half-reactions (Tro, Electrochemistry chapter).
- 27
How do you identify the oxidizing agent in a redox reaction?
The oxidizing agent is the species that is reduced and gains electrons in the reaction (Brown LeMay, Electrochemistry chapter).
- 28
How do you identify the reducing agent in a redox reaction?
The reducing agent is the species that is oxidized and loses electrons in the reaction (Zumdahl, Electrochemistry chapter).
- 29
What is the role of electroplating in galvanic cells?
Electroplating uses a galvanic cell to deposit a layer of metal onto a surface, often for decorative or protective purposes (Tro, Electrochemistry chapter).
- 30
What factors influence the efficiency of a galvanic cell?
Factors include the concentration of reactants, temperature, electrode surface area, and the presence of impurities (Brown LeMay, Electrochemistry chapter).
- 31
What is the role of electrodes in a galvanic cell?
Electrodes serve as the sites for oxidation and reduction reactions, facilitating the flow of electrons in the external circuit (Zumdahl, Electrochemistry chapter).
- 32
What is the significance of cell notation in galvanic cells?
Cell notation provides a shorthand representation of the components and reactions occurring in a galvanic cell, indicating the anode and cathode (Tro, Electrochemistry chapter).
- 33
How does the presence of a catalyst affect a galvanic cell?
A catalyst can increase the rate of the redox reactions occurring in the galvanic cell without being consumed in the process (Brown LeMay, Electrochemistry chapter).
- 34
What is the difference between a half-cell and a full cell?
A half-cell contains a single electrode and its electrolyte, while a full cell consists of two half-cells connected to allow for electron flow (Zumdahl, Electrochemistry chapter).
- 35
What is the purpose of using a porous membrane in a galvanic cell?
A porous membrane allows ions to pass between the half-cells while preventing the mixing of the two solutions, maintaining separation of reactants (Tro, Electrochemistry chapter).
- 36
What is the impact of increasing temperature on the spontaneity of a reaction in a galvanic cell?
Increasing temperature can shift the equilibrium and potentially increase the spontaneity of the reaction, depending on the enthalpy and entropy changes (Brown LeMay, Electrochemistry chapter).
- 37
What is the role of the external circuit in a galvanic cell?
The external circuit provides a pathway for electrons to flow from the anode to the cathode, allowing the cell to do electrical work (Zumdahl, Electrochemistry chapter).
- 38
How is the efficiency of a galvanic cell measured?
The efficiency of a galvanic cell is typically measured by comparing the useful work output to the energy input, often expressed as a percentage (Tro, Electrochemistry chapter).
- 39
What is the relationship between cell potential and equilibrium constant?
The relationship is given by the equation E°cell = (RT/nF) ln(K), where K is the equilibrium constant for the reaction (Brown LeMay, Electrochemistry chapter).
- 40
How does the concentration of products affect the cell potential?
Increasing the concentration of products will decrease the cell potential, as described by the Nernst equation (Zumdahl, Electrochemistry chapter).
- 41
What is the impact of electrode surface area on a galvanic cell's performance?
Increasing the electrode surface area can enhance the rate of the redox reactions, improving the overall performance of the galvanic cell (Tro, Electrochemistry chapter).