Hardening of oil is done by

Mustard gas is obtained by

Cyclohexene on reaction with $OsO_4$ followed by reaction with $NaHSO_3$ gives

Arrange the following compounds in the order of their reactivity towards electrophilic addition reaction with $HBr$.

In the reaction with $HCl$,an alkene reacts in accordance with the Markovnikov's rule to give a product $1-$chloro$-1-$methylcyclohexane. The possible alkene is

According to Markovnikov's rule,what is the product formed when $1$-butene reacts with water?