The electrolysis of molten compounds

1 mark · Normal

Which of the following half-equations correctly represents the reaction occurring at the anode during the electrolysis of molten potassium bromide (KBr)?

Show answer

Correct option: 2Br^- → Br_2 + 2e^-

Common mistakes: Writing only Br^- → Br_2 + 2e^- and missing stoichiometry; Confusing cathode and anode half-equations

Show mark scheme and worked solution

Marking points

B1 · 1 mark · Selects correct half-equation: 2Br^- → Br_2 + 2e^-

Worked solution

At the anode, each pair of Br^- ions loses two electrons to form Br_2: 2Br^- → Br_2 + 2e^-