$CH_3-CO-CH_2-CH_2-CH_2-CO_2H \xrightarrow[(ii) H_2O, H^+]{(i) NaBH_4} ?$
What will be the final product of this transformation?

Acid hydrolysis of $X$ yields two different organic compounds. Which one of the following is $X$?

Match the reactions given in Column-$I$ with the appropriate reagents in Column-$II$.
| Column-$I$ (Reaction) | Column-$II$ (Reagent) |
| :--- | :--- |
| $(A)$ $2CH_3COOH \rightarrow (CH_3CO)_2O$ | $(i)$ $(I) NH_3, (II) \Delta, -H_2O$ |
| $(B)$ Phthalic acid $\rightarrow$ Phthalamide | $(ii)$ $(I) Br_2 / \text{red phosphorous}, (II) H_2O$ |
| $(C)$ $CH_3CH_2COOH \rightarrow CH_3CHBrCOOH$ | $(iii)$ $Br_2 / FeBr_3$ |
| $(D)$ Benzoic acid $\rightarrow$ $m$-Bromobenzoic acid | $(iv)$ $H^+, \Delta \text{ OR } P_2O_5, \Delta$ |

What are $\underline{A}, \underline{B}, \underline{C}$ in the following reactions?
$(I)$ $(CH_3 CO_2)_2 Ca \stackrel{\Delta}{\longrightarrow} \underline{A}$
$(II)$ $CH_3 CO_2 H \underset{\text{Red P}}{\stackrel{HI}{\longrightarrow}} \underline{B}$
$(III)$ $2 CH_3 CO_2 H \stackrel{P_4 O_{10}}{\longrightarrow} \underline{C}$
$\underline{A} \quad \underline{B} \quad \underline{C}$

Considering the reaction sequence given below,the correct statement$(s)$ is(are):
$A$. $P$ can be reduced to a primary alcohol using $NaBH_4$.
$B$. Treating $P$ with conc. $NH_4OH$ solution followed by acidification gives $Q$.
$C$. Treating $Q$ with a solution of $NaNO_2$ in aq. $HCl$ liberates $N_2$.
$D$. $P$ is more acidic than $CH_3CH_2COOH$.

The correct acidity order of the following compounds is: