Total number of enol forms possible for the compound formed during the given reaction will be (including stereoisomers):
$CH_3MgBr + CH_3CH_2COCl \to$

What is the acid $(A)$ obtained in the following reaction sequence?
${C_2H_5I}$ $\xrightarrow{\text{alc. KOH}} X$ $\xrightarrow[CCl_4]{Br_2} Y$ $\xrightarrow{KCN} Z$ $\xrightarrow{H_3O^+} A$

Answer the following questions:
$(i)$ Give hybridization of Carbon atoms in the following compound: $CH_3-CH=CH-CH_2-C\equiv CH$
$(ii)$ Give the number of $\sigma$ and $\pi$ bonds in the above compound.
$(iii)$ Give the $IUPAC$ name of the above compound.
$(iv)$ Draw the geometrical isomers of the above compound.
$(v)$ Why are $cis$ and $trans$ isomers not possible in alkynes?
$(vi)$ Which bond possesses more bond length between $C=C$ and $C\equiv C$?

$A$ molecule $P$ on treatment with acid undergoes rearrangement and gives $Q$. $Q$ on ozonolysis followed by reflux under alkaline condition gives $R$. The structure of $R$ is given below:
[Image of $R$]
The structure of $P$ is

Product $(A)$ is

Which of the following gases is poisonous?