Which of the following is Baeyer's reagent?

Mustard gas is obtained by

Which of the following alkenes does $\underline{NOT}$ exhibit cis-trans isomerism?

The correct statement$(s)$ for the following addition reactions is(are):
$(i)$ $trans-but-2-ene \xrightarrow{Br_2/CHCl_3} M \text{ and } N$
(ii) $cis-but-2-ene \xrightarrow{Br_2/CHCl_3} O \text{ and } P$
[$A$] ($M$ and $O$) and ($N$ and $P$) are two pairs of diastereomers
[$B$] Bromination proceeds through trans-addition in both the reactions
[$C$] $O$ and $P$ are identical molecules
[$D$] ($M$ and $O$) and ($N$ and $P$) are two pairs of enantiomers

$CH_2=CHCl$ reacts with $HCl$ to form

Write a test to detect the presence of a double bond in a molecule.