[3.1.11] Electrode Potentials & Electrochemical Cells Flashcards
Electrode Potentials and Cells & Commercial Applications of Electrochemical Cells
What is an electrochemical cell?
Using the image below, describe why a voltage forms in this cell.
Why do we use a high-resistance voltmeter to measure potential differences?
What is a salt bridge?
What is it made of and what is one of its key properties?
Why isn’t a wire used instead of a salt bridge?
If in the image below the voltmeter were to be removed, what would happen?
Use a cell diagram to represent the electrochemical cell shown in the image below.
If a system does not include a metal that can act as an electrode, what is used instead? How does it work and why is it used?
Use a cell diagram to represent the reaction occurring at a half-cell below:
Use a cell diagram to represent the reaction occurring at a half-cell below:
Use a cell diagram to represent the reaction occurring at a half-cell below:
Use a cell diagram to represent the reaction occurring at a half-cell below:
How do we measure the electrode potential of a cell?
The potential of all electrodes is measured by comparing
their potential to that of the standard hydrogen electrode.
What are the conditions of the SHE, and why are these conditions needed?
How is the SHE represented in a cell diagram?
What is the hydrogen electrode equilibrium?
How do you calculate the EMF of a cell?
Calculate the EMF of the cell below:
What will the more negative half-cell always do?
What will the more positive half-cell always do?
Knowing this, what equation can you use to calculate the EMF?
- The more negative half cell will always oxidise.
- The more positive half cell will always reduce.
Using the E° values of the equations below, predict the direction of the redox reactions.
Using the E° values of the equations below, predict the direction of the redox reactions.
Where will the most powerful reducing agents and most powerful oxidising agents be found on an electrochemical series?
Using electrode data below explain why fluorine reacts with water.
Write an equation for the reaction that occurs and a conventional cell diagram too.
Use data from the table below to explain why chlorine should undergo a redox reaction with water.
Write an equation for this reaction.
Use the half equations below to explain in terms of oxidation state what happens to hydrogen peroxide when it is reduced.
What is the effect of concentration on Ecell?
What is the effect of temperature on Ecell?
Using the E° values below and the half-equations, write the overall reaction, calculate the EMF and show the conventional cell diagram of the lithium-manganese dioxide cell.
Using the E° values below and the half-equations, write the overall reaction that occurs when the lead acid cell discharges. Calculate its EMF too.
Using the E° values below and the half-equations, write the overall reaction when the nickel-cadmium cell discharges and recharges. Calculate its EMF too.
What are the simplified electrode reactions in a lithium cell?
In a lithium cell, at the positive electrode, there is an E° value of +0.6V and at the negative electrode, there is an E° value of -3.0V.
With the aid of these E° values, write the overall reaction that occurs when the lithium cell discharges and recharges. Calculate its EMF and show the conventional cell diagram.
What is a fuel cell?
Why don’t fuel cells need to be recharged?
What are the electrode reactions in an alkaline hydrogen-oxygen fuel cell?
What are the advantages of fuel cells?
What are the limitations of fuel cells?
