Answer : The correct answer is 3.
Explanation :
The given chemical reaction is,
![BrO^-_3(aq)\rightarrow Br^-(aq)+BrO^-_4(aq)](https://img.qammunity.org/2019/formulas/chemistry/high-school/88r7w1zxv0iq6dkzesfm3wik3au7bzsuiz.png)
In a disproportionate reaction, disproportionate substance is a single substance which is oxidized as well as reduced.
The oxidation state of Br in
is (+5).
The oxidation state of Br in
is (-1).
The oxidation state of Br in
is (+7).
In the given chemical reaction,
is getting reduced to
and
is getting oxidized to
. So, bromine is a disproportionate substance.
That means the bromine is present in three oxidation states.
Therefore, three oxidation states of the disproportionate substance have throughout the reaction.