Bromine is added to cold dilute aqueous solution of NaOH. The mixture is boiled. Which of the following statements is not true?
1. During the reaction bromine is present in four different oxidation states.
2. The greatest difference between the various oxidation states of bromine is 5.
3. On acidification of the final mixture, bromine is formed.
4. Disproportionation of bromine occurs during the reaction.
