The electrolysis of other molten substances
3 marks · EasyThis question is about the electrolysis of molten lithium bromide.
Name the particle that moves towards the anode.
State the element formed at the cathode.
Explain, using ions, how you know which element forms at the cathode.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) Bromide ion
(b) Lithium
(c) Lithium ions (Li^+) are attracted to the cathode, where they gain electrons to form lithium metal.
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Marking points
B1 (a) · 1 mark · Names bromide ion as the particle moving to the anode.
B2 (b) · 1 mark · Names lithium as the element formed at the cathode.
M1 (c) · 1 mark · Explains that Li^+ ions move to the cathode and are reduced to lithium metal.
Worked solution
a) Bromide ions (Br^-) move towards the anode.
b) Lithium forms at the cathode.
c) Lithium ions (Li^+) are attracted to the cathode and gain electrons to become lithium atoms.