$A$ compound has a vapour density of $29$. On warming with an aqueous solution of alkali,it gives a yellow precipitate. The compound is

An organic compound $A$ has the molecular formula $C_3H_6O$ and it undergoes the iodoform test. When saturated with dilute $HCl$,it gives $B$ with the molecular formula $C_9H_{14}O$. $A$ and $B$ respectively are:

The option$(s)$ with the correct sequence of reagents for the conversion of $P$ to $Q$ is(are):
$(A)$ $i$) Lindlar's catalyst,$H_2$; $ii$) $SnCl_2 / HCl$; $iii$) $NaBH_4$; $iv$) $H_3O^{+}$
$(B)$ $i$) Lindlar's catalyst,$H_2$; $ii$) $H_3O^{+}$; $iii$) $SnCl_2 / HCl$; $iv$) $NaBH_4$
$(C)$ $i$) $NaBH_4$; $ii$) $SnCl_2 / HCl$; $iii$) $H_3O^{+}$; $iv$) Lindlar's catalyst,$H_2$
$(D)$ $i$) Lindlar's catalyst,$H_2$; $ii$) $NaBH_4$; $iii$) $SnCl_2 / HCl$; $iv$) $H_3O^{+}$

Which of the following reagents would carry out the following transformation? ($D = $ $^2H$)

What are $X$ and $Y$ respectively in the following reactions?
$C_6H_5COOH \xrightarrow{X} C_6H_5CHO$
$C_6H_5CHO \xrightarrow[OH^-, 293 \ K]{C_6H_5COOH} Y \text{ (Major product)}$

Consider the following reaction sequence:
$4\text{-aminobenzonitrile}$ $\xrightarrow[(ii) H_2O]{(i) AlH(i-Bu)_2} 'A'$ $\xrightarrow[dil. NaOH, \Delta]{CH_3CHO} B$
The product $B$ is?