Identify the reagent used in the following conversion.

In the reaction sequence,
the major products $X$ and $Y$ respectively are

Identify the correct statements about $Z$ in the following reaction sequence:
$C_2H_5NH_2$ $\xrightarrow[NaNO_2 / HCl]{} X$ $\xrightarrow{H_2O} Y$ $\xrightarrow{Cu / 573 \ K} Z$
$I$. $Z$ is an aldehyde
$II$. $Z$ undergoes Cannizzaro reaction
$III$. $Z$ gives iodoform test
$IV$. $Z$ does not give test with Tollens' reagent

Which of the following gives an alcohol and salt of carboxylic acid when reacted with conc. $NaOH$?

Acetal or ketal is:

Which one of the following will most readily be dehydrated in acidic condition?