Electrochemical cells Flashcards
Where can metals who lose electrons most easily be found?
All metal atoms lose electrons to get a full outer energy level. Metals differ in their ability to lose electrons and those that lose electrons most easily are found at the top of the electrochemical series.
What is an electrical current?
A chemical reaction at the -ve end of the battery creates electrons. The electrons move around the circuit and are taken in by a reaction at the +ve end of the battery. This movement of electrons is an electrical current.
What is an electrolyte?
electrically conducting solutions containing ions are known as electrolytes.
What is the flow of electrons when two metals are placed together?
Electrons in an electrochemical cell flow in the external circuit from the species higher in the electrochemical series to the one lower in the electrochemical series.
What is an ion bridge?
Ions move across the ion or salt bridge to complete an electrical circuit.
What is the basis of the electrochemical cell?
An ion bridge.
What is a battery made off?
A battery is made up of two or more electrochemical cells.
What is voltage a measure of?
A voltage is a measure of the push a cell provides the current flowing through the wires.
What is voltage measured in?
The voltage is measured in volts (V).
Describe the relationship between voltage and a current?
The higher the voltage, the bigger the push and the bigger the current.
What is a half cell?
A half-cell is a metal in a solution of its own ions e.g. copper in copper sulfate.
Why is an electrochemical cell set up as two half cells?
To avoid any side (e.g. redox or precipitation reactions), the electrochemical cell can be set up as two half cells.
In an electrochemical cell by which reaction is electricity produced?
In an electrochemical cell, the electricity is produced by a redox reaction with oxidation happening in one half cell and reduction happening in the other.
What happens to the battery when one or more of the chemicals in an electrochemical cell are used up?
When one or more of the chemicals in an electrochemical cell are used up the battery will go flat.
Do electrochemical cells need to contain metals?
Electrochemical cells do not need to contain metals. A redox reaction with one half of the reaction losing electrons (oxidation) and the other half gaining electrons (reduction), separated by an ion bridge is all that is required to get electrons to flow through the external circuit.
