The product of the following reaction is :

Identify the symmetrical ketone from the following compounds.

Consider the following reaction sequence:
$\text{But-2-ene}$ $\xrightarrow{\text{ozonolysis}} X$ $\xrightarrow[(ii) H_3O^+]{(i) CH_3MgBr} Y$ $\xrightarrow[573 \ K]{Cu} Z$
The correct statements about $Z$ are:
$I$. It gives yellow precipitate with $I_2$ and $NaOH$ solution.
$II$. It undergoes disproportionation reaction in the presence of concentrated $NaOH$ solution.
$III$. It undergoes Wolff-Kishner reduction.
$IV$. It forms red precipitate with Fehling's reagent.

Which one of the following compounds does not give a primary alcohol on reduction?

Which of the following is an example of a conjugated diketone?

Which of the following on reaction with Grignard reagent followed by hydrolysis forms a secondary alcohol?