In the following reaction,compound $Q$ is obtained from compound $P$ via an ionic intermediate. What is the degree of unsaturation of $Q$?

The alkene formed as a major product in the below elimination reaction is

The order of decreasing reactivity in electrophilic addition of the following compounds is
$(I) \, Ph-CH=CH-COOH$
$(II) \, p-NO_2-C_6H_4-CH=CH-COOH$
$(III) \, p-MeO-C_6H_4-CH=CH-COOH$
$(IV) \, p-Cl-C_6H_4-CH=CH-COOH$

The most likely protonation site in the following molecule is:

State True or False for the following statements:
$(i)$ Positive and negative ions are formed by homolytic cleavage of a covalent bond.
$(ii)$ Positive and negative ions are formed by heterolytic cleavage of a covalent bond.
$(iii)$ Only homolytic cleavage is possible in the $C-Cl$ bond of $CH_3-Cl$.
$(iv)$ If heterolytic cleavage of a bond occurs,then ionic or polar type reactions take place.

An organic compound $A$,$C_5 H_8 O$,reacts with $H_2 O$,$NH_3$,and $CH_3 COOH$ as shown in the reaction scheme. Identify $A$.