When gas `A` is passed through dry `KOH` at low temperature, a deep red coloured compound, `B` and a gas care obtained. The gas `A`, on reaction with but-2-ene, followed by treatment with `Zn//H_2 O` yields acetaldehyde. Identify `A, B` and `C`.

Explanation

Gas `(A)` is ozone `(O_(3))`, since `(A)` on reductive ozonolysis gives acetaldehyde `(CH_(3)CHO)`
Gas`(A)+KOH("Dry")overset(Low)underset(temp.)rarr underset("coloured")underset(Deep-red)((B))+underset((gas))((C))`
`4O_(3)+4KOHrarr underset("Potassium")underset("ozonide")underset((B))(4KO_(3))+underset((C))(O_(2))`