Identify $A$ in the following chemical reaction:

What is the order of acidic strength for the following compounds?

Consider the following two reactions $A$ and $B$.
Numerical value of [molar mass of $x$ + molar mass of $y$] is . . . . . . .

Match the chemical conversions in List-$I$ with the appropriate reagents in List-$II$ and select the correct answer using the code given below the lists:
List-$I$:
$P$. $tert$-butyl chloride $\rightarrow$ isobutylene
$Q$. Sodium $tert$-butoxide $\rightarrow$ $tert$-butyl ethyl ether
$R$. $1$-methylcyclopentene $\rightarrow$ $1$-methylcyclopentanol
$S$. $1$-methylcyclopentene $\rightarrow$ $2$-methylcyclopentanol (trans-isomer)
List-$II$:
$1$. $(i) \ Hg(OAc)_2; (ii) \ NaBH_4$
$2$. $NaOEt$
$3$. $EtBr$
$4$. $(i) \ BH_3; (ii) \ H_2O_2/NaOH$
Codes: $P \quad Q \quad R \quad S$

$A$ new carbon-carbon bond formation is possible in

In the following reaction,$\text{Phenol}$ $\xrightarrow{Zn \, \text{dust}} x$ $\xrightarrow[\text{Anhy.} \, ZnCl_2]{CH_3Cl} y$ $\xrightarrow{\text{Alk.} \, KMnO_4} z$. The product $z$ is: