What is obtained by the dehydrohalogenation of allyl chloride?

The reaction conditions used for converting $1, 2-$dibromoethane to ethene are

What is the product obtained from the reaction of $HCl$,$HBr$,and $HI$ with alkenes in the presence of peroxide?

In the following sequence of reactions,the alkene affords the compound $B$.
$CH_3-CH=CH-CH_3$ $\xrightarrow{O_3} A$ $\xrightarrow[Zn]{H_2O} B$
The compound $B$ is:

The organic compound $5-$allylcyclohex$-3-$ene$-1-$ol is reacted with cold,dilute,aqueous solution of $KMnO_4$. The total number of hydroxyl group$(s)$ $(-OH)$ present in the product is

Isobutene in the presence of dilute $H_2SO_4$ forms an alcohol. The major product is