Halogens ~ Chemical Properties

Where is halogens found in the PT ?

In group 7 + ‘ salt former ‘

What is the oxidation number for halogen ?

Always - 1

Expect when it reacts with more reactive halogen or oxygen / peroxide

What color is Cl 2 chorine + state of matter

Cl2 is a pale green gas at room temp

What colour is Bromine Br 2 + state of matter

Dark red liquid at room temp ( only liquid non - metal )

Very volatile and readily form a red vapour

What colour is I2 iodine + state of matter

Forms a shiny black crystals at room temp

When warmed , iodine crystal sublime ( turn directly to a gas ) forming purple vapour

Compare other halogen with F - F bond

The F - F bond is very weak.

Cuz the fluorine atoms are very small and there’s a lot of repulsion between the bonding electrons

What does the term immiscible mean ?

when 2 liquids dos not mix together

What does displacement reaction mean ?

When a more reactive element displace a lower reactive element. It replaces the lower reactive element

Examples of displacement reaction in group 7

Potassium Chloride + Iodine. —→ Potassium iodide + Chlorine

Potassium Chloride + Bromine. ——> Potassium bromide + Chlorine

Potassium Bromide + Iodine. ——→ Potassium iodine + Bromine

Trends in existing ability ~ Halogen

Oxidizing ability of halogen decrease down the group , cuz atoms become larger ( less electronegative )

Halogen react by gaining electrons, which means they are oxidizing. THEMSELVEs are already reduced.

Chlorine will displace bromine

Cl2 + 2 NaBr —> 2 NaCl + Br2

Ionic equation : Cl 2 + 2 Na+ + 2 Br - ——→ Br2 + 2 Na+ + 2 Cl-

What is the Oxidising and reducing agent in the displacement of chlorine & bromine ?

Oxidising agent : Chlorine Cl2

Reducing agent : Bromide 2Br -