Draw structures of the following derivatives:
$(i)$ The $2,4-$dinitrophenylhydrazone of benzaldehyde
$(ii)$ Cyclopropanone oxime
$(iii)$ Acetaldehyde dimethyl acetal
$(iv)$ The semicarbazone of cyclobutanone
$(v)$ The ethylene ketal of hexan$-3-$one
$(vi)$ The methyl hemiacetal of formaldehyde

$A$ tertiary alcohol $H$ upon acid-catalysed dehydration gives a product $I$. Ozonolysis of $I$ leads to compounds $J$ and $K$. Compound $J$ upon reaction with $KOH$ gives benzyl alcohol and a compound $L$,whereas $K$ on reaction with $KOH$ gives only $M$.
$1.$ Compound $H$ is formed by the reaction of
$2.$ The structure of compound $I$ is
$3.$ The structures of compounds $J, K$ and $L$,respectively,are
$(A)$ $PhCOCH_3, PhCH_2 COCH_3$ and $PhCH_2 COO^{-} K^{+}$
$(B)$ $PhCHO, PhCH_2 CHO$ and $PhCOO^{-} K^{+}$
$(C)$ $PhCOCH_3, PhCH_2 CHO$ and $CH_3 COO^{-} K^{+}$
$(D)$ $PhCHO, PhCOCH_3$ and $PhCOO^{-} K^{+}$
Give the answer for questions $1, 2$ and $3.$

Which of the following reactions can be used to convert an unsaturated ketone into an unsaturated hydrocarbon?

One of the products of the following reaction is $P$. Structure of $P$ is

For the reaction given below:
The compound which is not formed as a product in the reaction is a:

$CH_3-CH(OH)-CH_2-CHO$
$3HCHO + A \xrightarrow[40^o C]{Na_2CO_3} (B) (82\%)$
Product $(B)$ of the above reaction is