The product obtained by dry distillation of calcium formate on reacting with ammonia yields

Arrange the following compounds in decreasing order of acidic character of $C-H$ bonds.
$CH_2=CH_2, CH_3-CH_3, C_6H_6, CH\equiv CH$

Provide a chemical test to distinguish between butane and but-$1$-ene and write the corresponding reactions.

"$P$" is a hydrocarbon with the molecular formula $C_8H_{14}$. On ozonolysis,"$P$" forms "$Q$". "$Q$" on treatment with alkali under reflux conditions produces "$R$",which on treatment with $I_2/NaOH$ gives a yellow precipitate. Acidification of the solution gives "$S$". The structure of "$S$" is given below:
(Structure $S$: $1-$methyl$-2-$oxocyclopentanecarboxylic acid derivative or similar cyclic structure as per common reaction pathways).
The correct structure of "$P$" is:

Product $A$ of the above reaction is

What is the major product of the following $E2$ reaction?