Identify $A$ in the reaction:

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

The reaction of propene with $H_3O^{+}$ proceeds through which of the following intermediates?

Identify the major products $X$ and $Y$ in the following reactions:
$(i)$ $C_6H_5-CH=CH_2 + HBr \rightarrow X$
(ii) $C_6H_5-CH_2-CH=CH_2 + HBr \xrightarrow{\text{Peroxide}} Y$

What are the $IUPAC$ nomenclature rules for naming alkenes?

The alkene that will give the same product with $HBr$ in the absence as well as in the presence of peroxide is