Haloform reaction is characteristic of

Identify the compound that exhibits tautomerism:

Cyclohexylamine when treated with nitrous acid yields $(P)$. On treating $(P)$ with $PCC$ results in $(Q)$. When $(Q)$ is heated with dilute $NaOH$,we get $(R)$. The final product $(R)$ is:

When two molecules of acetaldehyde condense in the presence of dilute alkali,it forms

Which of the following compounds on reaction with ammoniacal silver nitrate solution forms a precipitate of silver?

Identify the product $Y$ in the following reaction: $CH_3-CH=CH-CH_2-CHO + H_2 \xrightarrow{Ni} Y$