What is the common name for the reaction involving dehydrohalogenation of alkyl halides and dehydration of alcohols in the presence of an acid?

Identify the product $A$ in the following reaction:
$Methylenecyclohexane \xrightarrow{Br_2 / H_2O} A$

When ethanol is heated with conc. $H_{2}SO_{4}$,a gas is produced. The compound formed,when this gas is treated with cold dilute aqueous solution of Baeyer's reagent,is:

The percentage composition of an organic compound $A$ is: carbon = $85.71 \%$ and hydrogen = $14.29 \%$. Its vapour density is $14$. Consider the following reaction sequence:
$A$ $\xrightarrow{Cl_2/H_2O} B$ $\xrightarrow[(ii) H_3O^+]{(i) KCN/EtOH} C$
Identify $C$.

Identify product $C$ in the following reaction: Propylene dibromide $\xrightarrow[\text{Alcohol}]{Zn, \Delta} A$ $\xrightarrow{HBr} B$ $\xrightarrow{Na, \text{ether}} C$

The reaction of $4$-methyloct$-1-$ene $(P, 2.52 \ g)$ with $HBr$ in the presence of $(C_6H_5CO_2)_2O_2$ gives two isomeric bromides in a $9:1$ ratio,with a combined yield of $50 \%$. Of these,the entire amount of the primary alkyl bromide was reacted with an appropriate amount of diethylamine followed by treatment with aqueous $K_2CO_3$ to give a non-ionic product $S$ in $100 \% $ yield. The mass (in $mg$) of $S$ obtained is. . . . . . . [Use molar mass (in $g \ mol^{-1}$) : $H=1, C=12, N=14, Br=80$]