Chapter 4 - Cells and Batteries

Define a cell ?

a system that contains chemicals which react and produce electricity

What is a cell composed of ?

A cell contains two different electrodes in contact with an electrolyte

What is voltage ?

The charge difference between 2 different metals (electrodes) submerged in an electrolyte

The difference in reactivity of the electrodes is _______ ____________ to the voltage of the cell

Directly proportional

Left side electrode is the ?

Least reactive

Right side electrode is the ?

Most reactive

What does it mean if the voltage is negative ?

The most reactive metal as been placed in the left side of the table

What 2 factors does the voltage of a cell depend on ?

• concentration of ions in the electrolyte

• Identity of the metal electrodes

Define a battery ?

It is 2 or more cells connected together in series

What is the voltage of a battery ?

The voltage of the cells added together

Why are non-rechargeable batteries so ?

• the chemical reaction in a cell is irreversible

• Overtime as the reaction occurs the metal ions in the electrode and ions in the electrolyte get used up (formed into products of the reaction)

• Because one of the reactants has been used up the reaction cannot occur , therefore no electricity is produced

• The products can be reformed into the reactants so the batter cannot be recharged

How are rechargeable batteries charged ?

By connecting them to an external electrical current

What is a fuel cell ?

an electrical cell that's supplied with a fuel and oxygen (or air) and efficiently transfers the energy released by the reaction between them as electricity.