The electrolysis of molten compounds
3 marks · EasyThe diagram shows the apparatus used to electrolyse molten lithium iodide ().
Answer the following questions about this electrolysis.
Name the ion in molten that is attracted to the cathode.
State what is formed at the anode.
Write the half-equation for the reaction 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.
Show answer
(a)
(b) Iodine or I_2
(c)
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Correctly identifies as moving to the cathode.
B1 (b) · 1 mark · States iodine (I_2) as the product at the anode; allow 'iodine gas' or 'I_2'.
B1 (c) · 1 mark · Writes correct half-equation for the cathode: .
Worked solution
a) The cation in is , which is attracted to the cathode.
b) At the anode, iodide ions lose electrons to form iodine gas ().
c) The half-equation at the cathode is: .