Among the given compounds,the correct order of enol content is:
$(I)$ Cyclopentanone
$(II)$ $4$-hydroxycyclopent-$2$-en-$1$-one derivative
$(III)$ $\gamma$-butyrolactone derivative

What type of fission is possible by sunlight?

Predict the major product of the following reaction:

In the reaction given below,the total number of atoms having $sp^2$ hybridization in the major product $P$ is. . . . .

Different possible thermal decomposition pathways for peroxyesters are shown below. Match each pathway from List-$I$ with an appropriate structure from List-$II$ and select the correct answer using the code given below the lists.
List-$I$:
$P$. Pathway $P$
$Q$. Pathway $Q$
$R$. Pathway $R$
$S$. Pathway $S$
List-$II$:
$1$. $C_6H_5CH_2CO_3CH_3$
$2$. $C_6H_5CO_3CH_3$
$3$. $C_6H_5CH_2CO_3C(CH_3)_2CH_2C_6H_5$
$4$. $C_6H_5CO_3C(CH_3)_2C_6H_5$
Codes:
$P \quad Q \quad R \quad S$
$A. 1 \quad 3 \quad 4 \quad 2$
$B. 2 \quad 4 \quad 3 \quad 1$
$C. 4 \quad 1 \quad 2 \quad 3$
$D. 3 \quad 2 \quad 1 \quad 4$

Fill in the blanks:
$(1)$ ......... is the name of $C_6H_5Br_2$.
$(2)$ .......... and ......... are the suffixes for aldehyde and hydroxyl functional groups,respectively.
$(3)$ $A$ is formed by homolytic fission,while $B$ is formed by heterolytic fission of the $C-Cl$ bond in $CH_3-Cl$.
$(4)$ The fission of a covalent bond is of ......... and ......... type.