Download 1 - Rosshall Academy

3.3(a) Redox Learning Outcomes
In all cases pupils should be able to state that:
The electrochemical series
1
Electricity can be produced by connecting different metals
together, with an electrolyte, to form a simple cell.
2
The voltage between different pairs of metals varies and
this leads to the electrochemical series.
3
Electricity can be produced in a cell by connecting two
different metals in solutions of their metal ions.
4
Electricity can be produced in a cell when at least one of
the half-cells does not involve metal atoms.
5
Electrons flow in the external circuit from the species
higher in the electrochemical series to the one lower in the
electrochemical series.
6
The purpose of the ‘ion bridge’ (salt bridge) is to allow the
movement of ions to complete the circuit.
Redox reactions
7
Oxidation is the loss of electrons by any reactant in a
chemical reaction.
8
A metal element reacting to form a compound is an example
of oxidation.
9
Reduction is a gain of electrons by a reactant in any
reaction.
10
A compound reacting to form a metal is an example of
reduction.
11
In a redox reaction, oxidation and reduction occur
together.
12
Ion-electron equations can be written for oxidation and
reduction reactions.
13
Ion-electron equations can be combined to produce redox
equations.
14
Chemical cells are examples of redox reactions
15
A simple cell can be set up to investigate which factors
might affect the size of the voltage produced by the cell.
16
One factor that can be investigated is to find out if
different pairs of metals produce different voltages.
17
Another factor could be to investigate whether the
electrolyte affects the size of the voltage produced.
Displacement
18
Displacement reactions occur when a metal is added to a
solution containing ions of a metal lower in the
electrochemical series.
19
Displacement is another example of a redox reaction.
20
The reaction of metals with acids can establish the position
of hydrogen in the electrochemical series.
Electrolysis
21
Electrolysis is when electricity is passed through a solution
to break it up into elements.
22
Electrolysis is another example of a redox reaction.
23
During electrolysis, oxidation occurs at the positive
electrode and reduction occurs at the negative electrode.