Consider the following three halides:
($\mathrm{i}$) ${\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{Cl}$
($\mathrm{ii}$) ${\mathrm{CH}}_2=\mathrm{CH}-\mathrm{Cl}$
($\mathrm{iii}$)${\mathrm{C}}_6{\mathrm{H}}_5-\mathrm{Cl}$
Arrange the $\mathrm{C}-\mathrm{Cl}$ bond length of these compounds in the decreasing order.

The order of acidity of compounds $\mathrm{I}-\mathrm{IV}$ is

The correct order of acidity of the following compounds is:

The correct order of acidity of the three groups (marked $\mathrm{X}, \mathrm{Y}, \mathrm{Z}$) in the given species is: