chlorine exists in several oxidation states: -1, +1, +3, +4, +5, and +7. the -1 state is most often in chloride. chlorides are not reactive. compounds containing chlorine in its +1 oxidation state are hypochlorites. only one is common. they are a strong oxidizing agent, as are all + oxidation state compounds. +3 is in chlorites. +4 is in chlorine dioxide, a common chlorine compound that is not a chloride. +5 is in chlorates. +7 is in perchlorates. hypochlorites are most reactive, while perchlorates are the least reactive.