Edexcel IAL Chemistry A2 6.P1 practical problem solving

Pearson Edexcel IAL Chemistry syllabusChemistry YCH11First assessment 2019
Only one direct question exists, so focus narrowly on the practical reasoning: iodide reacts rapidly with manganate(VII), using it up and stopping the ethanedioate reaction.
How this is tested
- Explain how iodide reacts with MnO4- so the ethanedioate reaction is stopped.