Which is the most suitable reagent for the following transformation?
$CH_3-CH=CH-CH_2-CH(OH)-CH_3 \rightarrow CH_3-CH=CH-CH_2-COOH$

The correct order of decreasing acidity of the following aliphatic acids is $:-$

$2,2-$ Dimethylpropanoic acid on heating with sodalime gives:

$A$ compound $(A)$ has the molecular formula $C_2H_4O_2$ and it gives the following reactions:
$(i)$ Addition of the above compound to a sodium carbonate solution gives effervescence of $CO_2$ gas and forms compound $(P)$.
$(ii)$ When compound $(P)$ is heated with sodalime,it gives gas $(Q)$. Identify $(A)$,$(P)$,and $(Q)$ and provide the reactions.

In which of the following reactions will cyanide be obtained as a major product?

The product $(Q)$ is