The electrolysis of aqueous solutions
3 marks · EasyThe electrolysis of concentrated sodium chloride solution is carried out using carbon electrodes.
State the product formed at the cathode.
State the product formed at the anode.
Write a word equation for the reaction that occurs at the anode.
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(a) Hydrogen · must show correct identification of hydrogen
(b) Chlorine · must show correct identification of chlorine
(c) Chloride ions → chlorine + electrons · must show word equation for chloride at anode, reactants and products stated
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Marking points
B1 (a) · 1 mark · Hydrogen stated as the product at the cathode.
B1 (b) · 1 mark · Chlorine stated as the product at the anode.
B1 (c) · 1 mark · Correct word equation for anode reaction: 'Chloride ions → chlorine + electrons' or 'Chloride ions lose electrons to form chlorine.'
Worked solution
a) Product at cathode: Hydrogen b) Product at anode: Chlorine c) Word equation at anode: Chloride ions → chlorine + electrons