Electrochemical Cells
Mission 1: Electrochemical Cells
Mission Objectives. You should be able to...
1. Construct and annotate both types of electrochemical cells.
2. Explain how a redox reaction is used to produce electricity in a voltaic cell and how current is conducted in an electrolytic cell.
3. Distinguish between electron and ion flow in both electrochemical cells.
4. Deduce the products of the electrolysis of a molten salt.
5. Explain the process of electroplating.
EMF: electromotive force, (aka voltage) which is the energy supplied by a source divided by the electric charge transported through the source. In a voltaic cell, the EMF is equal to the electric potential difference for zero current. Electrons take the path of least resistance. Difference between high potential energy and low potential energy is the EMF.
In voltaic cells, a cell potential is generated, resulting in the movement of electrons from the anode to the cathode via the external circuit. The cell potential is defined as the potential difference between the cathode and the anode when the cell is operating and is always less that the cell's maximum voltage. Under standard conditions (1M, 298K) the cell potential is called the standard cell potential, represented by (Ecell). To calculate Ecell, you will need the potentials for the oxidation reaction and the reduction reaction.
Ecell = Ecathode - Eanode OR as your book states: Ecell = Erhe - Elhe. Rhe means right hand electrode and lhe means left hand electrode. I prefer the first equation. The cathode is usually more positive and the anode is usually less positive. You need to reference the standard cell potentials table in your data booklet.
Below is a series of vids that go into detail about electrochemical cells. We will work our way through them.
Mission Objectives. You should be able to...
1. Construct and annotate both types of electrochemical cells.
2. Explain how a redox reaction is used to produce electricity in a voltaic cell and how current is conducted in an electrolytic cell.
3. Distinguish between electron and ion flow in both electrochemical cells.
4. Deduce the products of the electrolysis of a molten salt.
5. Explain the process of electroplating.
EMF: electromotive force, (aka voltage) which is the energy supplied by a source divided by the electric charge transported through the source. In a voltaic cell, the EMF is equal to the electric potential difference for zero current. Electrons take the path of least resistance. Difference between high potential energy and low potential energy is the EMF.
In voltaic cells, a cell potential is generated, resulting in the movement of electrons from the anode to the cathode via the external circuit. The cell potential is defined as the potential difference between the cathode and the anode when the cell is operating and is always less that the cell's maximum voltage. Under standard conditions (1M, 298K) the cell potential is called the standard cell potential, represented by (Ecell). To calculate Ecell, you will need the potentials for the oxidation reaction and the reduction reaction.
Ecell = Ecathode - Eanode OR as your book states: Ecell = Erhe - Elhe. Rhe means right hand electrode and lhe means left hand electrode. I prefer the first equation. The cathode is usually more positive and the anode is usually less positive. You need to reference the standard cell potentials table in your data booklet.
Below is a series of vids that go into detail about electrochemical cells. We will work our way through them.
Gibbs' Free Energy and Cell Potential
There are examples of the electrolysis of aqueous solutions (see below). You're required to understand the setup of the cells and the observations at each electrode, and you should be familiar with the industrial uses of these processes.
A. Electrolysis of aqueous sodium chloride (p. 422-424)
B. Electrolysis of aqueous copper (II) sulfate ( p. 425-428)
C. Electrolysis of water (p. 428-429)
The following factors affect the amount of product formed at the electrodes during electrolysis: current (I), duration of electrolysis (t), and charge on the ion (z).
A. Electrolysis of aqueous sodium chloride (p. 422-424)
B. Electrolysis of aqueous copper (II) sulfate ( p. 425-428)
C. Electrolysis of water (p. 428-429)
The following factors affect the amount of product formed at the electrodes during electrolysis: current (I), duration of electrolysis (t), and charge on the ion (z).
Electroplating
This is a process that uses electrolysis to deposit a layer of one metal on top of another metal. This is done to cover a metal with a decorative, more expensive or corrosion-resistant layer of another metal. Silver plating a spoon uses a silver anode and an iron spoon cathode (Pearson, 2014). The below video walks you through the setup.
This is a process that uses electrolysis to deposit a layer of one metal on top of another metal. This is done to cover a metal with a decorative, more expensive or corrosion-resistant layer of another metal. Silver plating a spoon uses a silver anode and an iron spoon cathode (Pearson, 2014). The below video walks you through the setup.