Halogen Displacements Flashcards
what happens in a displacement reaction?
more reactive halogens can displace less reactive halogens from their compounds
what colour is the halogen chlorine (aq)?
colourless
what colour is halogen bromine (aq)?
yellow
what colour is the halogen iodine (aq)?
brown
what colour is the salt potassium chloride (KCl) (aq)?
colourless
what colour is the salt potassium bromide (KBr) (aq)?
colourless
what colour is the salt potassium iodide (KI) (aq)?
colourless
what reaction happens between KCl and Br2?
no change - stays yellow
what reaction happens between KCl and I2?
no change - stays brown
what reaction happens between KBr and Br2?
Cl2 + 2KBr -> Br2 + KCl
- chlorine displaces bromine
- colourless -> yellow
what reaction happens between KBr and I2?
no change - stays brown
what reaction happens between KI and I2?
Cl2 + 2Kl -> I2 + 2KCl
- chlorine displaces bromine
- colourless -> yellow
what reaction happens between KI and Br2?
Br2 + 2KI -> I2 + 2KBr
- bromine displaces iodine
- yellow -> brown
why does displacement occur?
because the halogen added is more reactive than the halogen present in the salt
what is the reactivity trend with iodine, chlorine and bromine?
chlorine > bromine > iodine
what determines the colour change in halogen displacements?
the halogens present - the salts are all colourless
what happens to the colour of halogens when no change occurs in a reaction?
the colour of the halogen initially present remains
what type of reaction is a halogen displacement reaction?
redox reaction
what happens in a redox reaction?
the more reactive halogen atom steals an electron from the halide ion in the salt
what is redox reaction short for?
REDuced an OXidised
