The element at its highest oxidation state will not under goes disproportionation reaction . in ClO4- Cl(+7)is at its highest oxidation state . then element in its intermediate oxidation state will under goes to disproportionation reaction

Disproportionation Reaction:
Disproportionation reaction is a type of redox reaction in which a single species is both oxidized and reduced simultaneously, resulting in the formation of two different oxidation states of the same element.

The following species do not show disproportionation reaction and the reasons are explained below:

1. ClO- (Hypochlorite ion):
- In the hypochlorite ion, chlorine has an oxidation state of +1.
- The disproportionation reaction for ClO- can be represented as follows:
2ClO- → Cl- + ClO3-
- However, this reaction does not occur spontaneously. It requires external energy or a suitable catalyst to proceed. Without an energy source or catalyst, ClO- does not undergo disproportionation.

2. ClO2- (Chlorite ion):
- In the chlorite ion, chlorine has an oxidation state of +3.
- The disproportionation reaction for ClO2- can be represented as follows:
2ClO2- → ClO- + ClO3-
- Similar to ClO-, this reaction does not occur spontaneously and requires external energy or a suitable catalyst to proceed.

3. ClO3- (Chlorate ion):
- In the chlorate ion, chlorine has an oxidation state of +5.
- The disproportionation reaction for ClO3- can be represented as follows:
4ClO3- → 3ClO4- + Cl-
- This reaction does not occur spontaneously as well and requires external energy or a suitable catalyst.

4. ClO4- (Perchlorate ion):
- In the perchlorate ion, chlorine has an oxidation state of +7.
- The perchlorate ion does not undergo disproportionation under normal conditions. It is a stable species and does not readily react with other species to form different oxidation states of chlorine.

Summary:
- ClO-, ClO2-, and ClO3- do not show disproportionation reactions under normal conditions. These reactions require external energy or a suitable catalyst to proceed.
- ClO4- (perchlorate ion) is a stable species and does not undergo disproportionation under normal conditions.