On heating $KClO_3$,we get

Aqua-regia reacts with $Pt$ to yield

The reaction of $HClO_3$ with $HCl$ gives a paramagnetic gas,which upon reaction with $O_3$ produces

When a mixture of solid $NaCl$ and solid $K_2Cr_2O_7$ is heated with concentrated $H_2SO_4$,orange-red vapours are evolved. These vapours are of which compound?

Chlorine cannot be used:

The bleaching action of bleaching powder is due to the formation of