1. 3.3.1 Chem. Properties of groups
Chem. Properties of groups
•Discuss the similarities and differences
in the chemical properties of elements
in the same group

2. Oxidizing ability of halogens
In displacement reactions between halogens and
halides, the halogen acts as an oxidizing agent.
increasing oxidizing ability
fluorine
This means that the halogen:
 oxidizes the halide ion to the halogen
chlorine
 gains electrons
bromine
 is reduced to form the halide ion.
What is the order of oxidizing ability of the
halogens?
iodine

3. Halogen displacement reactions
Halogen displacement reactions are redox reactions.
Cl2 + 2KBr → 2KCl + Br2
To look at the transfer of electrons in this reaction, the following two half equations can
be written:
Cl2 + 2e- → 2Cl- 2Br- → Br2 + 2e-
What has been oxidized and what has been reduced?
 Chlorine has gained electrons, so it is reduced to Cl- ions.
 Bromide ions have lost electrons, so they have been oxidized to bromine.