$C_6H_6$ $\xrightarrow[AlCl_3]{(CH_3)_2CHCOCl}$ $\xrightarrow[\text{reduction}]{\text{Clemmensen}}$ $\xrightarrow[AlCl_3]{CH_3COCl}$ $\xrightarrow[\text{Red } P + HI]{H_3O^{\oplus}} (\text{Ibuprofen})$
Ibuprofen is

The increasing order of the acidity of the following carboxylic acids is:

In the following reaction,$X$ and $Y$ are respectively
$CH_3 COOH + NH_3$ $\longrightarrow X \stackrel{\Delta}{}$ ${\longrightarrow} Y + H_2 O$

When compound $X$ is oxidised by acidified potassium dichromate,compound $Y$ is formed. Compound $Y$ on reduction with $LiAlH_4$ gives $X$. $X$ and $Y$ respectively are:

Match Column-$I$ with Column-$II$ :
| Column-$I$ | Column-$II$ |
| :--- | :--- |
| $(A)$ Cyclopentanone + $2,4-$$DNP$ $\xrightarrow{\text{mild } H^+}$ Cyclopentanone$-2,4-$$DNP$ derivative | $(P)$ Electrophilic substitution |
| $(B)$ $4-$phenyl$-2-$methylbutan$-2-$ol $\xrightarrow{\text{Conc. } H_2SO_4}$ $1,1-$dimethyl$-1,2,3,4-$tetrahydronaphthalene | $(Q)$ Nucleophilic substitution |
| $(C)$ $4-$chlorocyclohexanethiol $\xrightarrow{\text{Base}}$ $7-$thiabicyclo[$2.2$.$1$]heptane | $(R)$ Nucleophilic addition |

The reaction sequence$(s)$ that would lead to $o$-xylene as the major product is (are)