Q.
A greenish yellow gas reacts with an alkali metal hydroxide to form a halate which can be used in fire works and safety matches. The gas and halate respectively are
The gas is Cl2 and the halate used in fire works and safety matches is KClO3 greenish yellowgas3Cl2+6KOH→pot.chlorate (Halate)KClO3+5KCl+3H2O
As bromine is reddish liquid and I2 is violet solid so they are ignored here.