Chemistry - Halogen Displacement Reactions

Edexcel IGCSE Chemistry

what is a halogen displacement reaction?

a more reactive halogen displaces a less reaction halogen from a solution of it’s salts

what is the equation for a displacement reaction between chlorine and potassium iodide?

• chlorine + potassium iodide → potassium chloride + iodine

• Cl2 + 2KI → 2KCl + I2

why does chlorine displace iodine?

beacuse chlorine is more reactive

name the group 7 elements in order from most reactive to least reactive

1. fluorine

2. chlorine

3. bromine

4. iodine

5. (astatine)

what happens to the electron shells of group 7 elements when they take part in a reaction?

the outershell gains an eletron and forms an anion

the less easily these anions form …

… the less reactive the elements is

explain the reactivity trend of the halogens?

• atoms become larger down the group

• the outershell moves further away from the nucleus

• force of attraction between the nucleus and outershell decreases

• outer electron is gained less easily

• halogen becomes less reactive

what is a redox reaction?

where oxidation and reduction happen at the same time

in this equation which ion is the spectator ion?

K+

in the equation what ion is being reduced?

Chlorine

in the equation what ion is being oxidised?

Bromine