Halogen Displacement Reactions Flashcards
All 5 cards in this deck
What is a halogen displacement reaction?
A more reactive halogen takes the place of a less reactive halogen in a solution of its halide, e.g. chlorine + sodium bromide → sodium chloride + bromine.
What are the steps to predict the outcome of adding a halogen to a halide solution?
e.g. chlorine water added to potassium iodide solution
- Compare positions in group 7: chlorine is above iodine, so more reactive.
- More reactive halogen displaces the less reactive one: chlorine displaces iodine.
- Products: potassium chloride + iodine — the solution turns brown.
True or false? Bromine displaces chlorine from sodium chloride solution.
False. Bromine is less reactive than chlorine, so no reaction occurs.
Will astatine displace iodine from potassium iodide solution?
No — astatine is below iodine in group 7, so it is less reactive and no reaction occurs.
What is seen when chlorine water is added to colourless potassium bromide solution, and why?
The solution turns orange. Chlorine is more reactive than bromine, so it displaces bromine from the bromide, and the bromine colours the solution.