Cells and batteries

Question 1

What is an electrochemical cell

Answer 1

A system made up of 2 different electrodes in contact with an electrolyte

Question 2

How electrochemical cells work

1. The 2 … must be able to conduct … (normally … are used)
2. The … is a liquid that contains … which … with the …
3. The … reactions between the … and the electrolyte set up a … difference between the …
4. If the electrodes are … by a … the … is able to … and … is produced

Answer 2

1. The 2 electrodes must be able to conduct electricity (normally metals are used)
2. The electrolyte is a liquid that contains ions which react with the electrodes
3. The chemical reactions between the electrodes and the electrolyte set up a charge difference between the electrodes
4. If the electrodes are connected by a wire the charge is able to flow and electricity is produced

Question 3

What causes a difference in charge in electrochemical cells

Answer 3

Different metals react differently with the same electrolyte

Question 4

How is a battery formed

Answer 4

By connecting 2 or more cells together in series

Question 5

What happens in non rechargeable batteries

-the … reactions that happen at the … are …
-over time the … particles (ions in the … and the … ion on the …) get used …up and turned into the …
-once one of the … is used up the … can’t happen … so no … is produced
-the … can’t be turned back into the … so the … can’t be …

Answer 5

-the chemical reactions that happen at the electrodes are irreversible
-over time the reacting particles (ions in the electrolyte and the metal ion on the electrode) get used up and turned into the products
-once one of the reactants is used up the reaction can’t happen anymore so no electricity is produced
-the products can’t be turned back into the reactants so the cell can’t be recharged

Question 6

What happens in a rechargeable cell

The … can be … by … it to an … electric …

Answer 6

The reaction can be reversed by connecting it to an external electric current