Paxman: Green vitriol is the hepta-hydrate of which ferrous salt?
Birmingham captain: Iron sulphate (in a questioning tone of voice).
Paxman: No, it's just sulphate.
OK so its correct name is Iron(II) sulphate, but he's accepted far more inaccurate answers than that in the past. Birmingham eventually lost by 10 points so the 5 points for this question wouldn't quite have made the difference but it was jolly close.