$CH_3CHO$ reacts with aqueous $NaOH$ solution to form

The reaction sequence is as follows:
$Cyclopentanecarboxamide$ $\xrightarrow{P_2O_5, \Delta} W$ $\xrightarrow{CH_3MgBr, H_3^+O} X$ $\xrightarrow{Ca(OH)_2, I_2 (\text{yellow ppt.})} Y$ $\xrightarrow{\Delta} Z$
$Z$ is:

Which of the following compounds has the highest boiling point?

Arrange the following compounds in the increasing order of their reactivity towards the nucleophilic addition of $HCN$:
$1. HCHO$
$2. CH_3COCH_3$
$3. PhCOCH_3$
$4. PhCOPh$

Considering the following reaction sequence,the correct statement$(s)$ is(are):
$A$. Compounds $P$ and $Q$ are carboxylic acids.
$B$. Compound $S$ decolorizes bromine water.
$C$. Compounds $P$ and $S$ react with hydroxylamine to give the corresponding oximes.
$D$. Compound $R$ reacts with dialkylcadmium to give the corresponding tertiary alcohol.

The reaction sequence is as follows:
Benzene + $CH_3COCl$ $\xrightarrow{\text{Anhydrous } AlCl_3} (A)$ $\xrightarrow{(x)} \text{Ethylbenzene}$.
Reagent $(x)$ can be: