6 This question is about electrolysis.
Molten sodium chloride is electrolysed in an industrial process to produce sodium.
Figure 8 shows a simplified version of the electrolysis cell used.
Figure 8
6-1 Which is the correct half equation for the production of sodium?
[1 mark]
ANSWER
Na+ e− → Na
6-2 Suggest one reason why the products of the electrolysis must be kept apart.
[1 mark]
ANSWER
So the products do not react to reform sodium chloride.
6-3 Which type of particle passes through the mesh in the electrolysis of molten sodium chloride?
[1 mark]
ANSWER
Ions
Aqueous sodium chloride solution is 4lectrolyzed in a different industrial process.
Two gases and an alkaline solution are produced.
6-4 Which two ions are present in aqueous sodium chloride solution in addition to sodium ions and chloride ions?
[2 marks]
ANSWER
H+ (Hydrogen Ion);
OH- (Hydroxide Ion).
6-5 Name the alkaline solution produced.
[1 mark]
ANSWER
Sodium hydroxide
6-6 Explain how the alkaline solution is produced.
You should refer to the processes at the electrodes.
[3 marks]
ANSWER
Sodium ions and hydroxide ions are left in solution because) hydrogen ions which are positively charged are discharged / reduced at the negative electrode (Cathode) to form hydrogen whereas chloride ions are discharged / oxidized at the positive electrode (Anode) to form chlorine.
