What is the product formed by the reaction of $C_6H_5CH = CHCH_3$ with $HBr$?

Arrange the following compounds in order of decreasing rate of hydrolysis for $S_N1$ reaction:
$(i)$ $C_6H_5CH_2Br$
(ii) $p-CH_3-C_6H_4-CH_2Br$
(iii) $p-CH_3CH_2-C_6H_4-CH_2Br$
(iv) $p-(CH_3)_2CH-C_6H_4-CH_2Br$

The following bimolecular elimination reaction $(E_2)$ is carried out with different halogen leaving groups. The per cent yield of the two products ($2$-hexene and $1$-hexene) for each leaving group is listed below.

Leaving group	Conj. Acid $pK_a$	$\%$-yield of $2$-hexene	$\%$-yield of $1$-hexene
$X = I$	$-10$	$81\%$	$19\%$
$X = Br$	$-9$	$72\%$	$28\%$
$X = Cl$	$-7$	$67\%$	$33\%$
$X = F$	$3.2$	$30\%$	$70\%$

Which of the following statement$(s)$ is/are true concerning this series of $E_2$ reactions?

Which one of the following is most reactive towards nucleophilic substitution reaction?

What type of hybridisation is present in the carbocation formed during the alkaline hydrolysis of $1-$bromo$-1-$phenylethane?

Which reaction results in the formation of a pair of enantiomers?