Step 1: Identifying the Oxidising Agent and Reducing Agent
Oxidising Agent: Bromine water
Reducing Agent: Iron(II) sulphate
Step 2: Determining the Oxidation and Reduction Process and Predicting the Observation
The reducing agent undergoes oxidation
Fe2+ + 2e --> Fe3+
Observation: The green colour of iron(II) sulphate solution turn brown.
Note: Iron(II) ion is green in colour whereas iron(III) ion is brown in colour.
The oxidising agent undergoes reduction
Br2 + 2e --> 2Br-
Observation: The yellow/orange colour of bromine water become colourless.
Note: Bromine is yellow/orange in water whereas bromide is colourless.
Step 3: Identifying the Anode and Cathode
Electrode P: Anode
Electrode Q: Cathode
Note: Oxidation occurs at anode whereas reduction occurs at cathode.
Step 4: Determine the positive and Negative Terminal
Positive Terminal: Electrode Q
Negative Terminal: Electrode P
Note: Anode is the negative terminal whereas cathode is the positive terminal.
Step 5: Determine the Direction of Flow of Electrons.
From electrode P to electrode Q.
Note: Electrons flow from the negative terminal to the positive terminal through the wire.