A greenish yellow gas reacts with alkali metal hydroxide to form palate which can be used in fire works and safety matches, the gas and halt respectively are _____?

Chlorine gas is greenish yellow in color.Halate ion which will be chlorate ion in this case is ClO3-So option (2) is correct.Following is the reaction with hot and conc. alkali hydroxide solution.Cl2+KOH→KCl+KClO3Non metals usually disproportionate in alkali.