Among the following compounds,the one$(s)$ that give$(s)$ effervescence with aqueous $NaHCO_{3}$ solution is (are):
$I. (CH_{3}CO)_{2}O$
$II. CH_{3}COOH$
$III. PhOH$
$IV. CH_{3}COCHO$

In the following reaction,$X$ and $Y$ respectively are:
$C_2H_5OH$ $\xrightarrow{KMnO_4 / H^+} X$ $\xrightarrow{C_2H_5OH / H_2SO_4, \Delta} CH_3COOC_2H_5$

When carboxylic acid reacts with organolithium reagents to give ketones,side reactions sometimes occur. For example,
$HOCH_2CH_2CH(CH_3)CH_2CH_2COOH$ $\xrightarrow[(x) \, CH_3Li]{tetrahydro\,furan}$ $\xrightarrow[NH_4Cl]{H_2O}$ $\underset{63\%}{\text{Compound } A: HOCH_2CH_2CH(CH_3)CH_2CH_2COCH_3}$ + $\underset{37\%}{\text{Compound } (B)}$
The value of $(x)$ in the above reaction is:

Arrange the following compounds in order of their reactivity toward $LiAlH_4$:
$(i)$ Cyclopentanone
(ii) $N$-Methylpyrrolidin$-2-$one
(iii) $\gamma$-Butyrolactone

In the reaction,if $X$ is the reagent and $Y$ is the product,which of the following is not feasible?

Which among the following is used as a food preservative?