Question

Rank the following compounds in order of decreasing electron density in the benzene
(I) Chlorobenzene (II) $4$ - nitrochlorobenzene
(III) $2,4$ - dinitrochlorobenzene (IV) $2,4,6$ - trinitrochlorobenzene

• A. I > II > III > IV
• B. I > III > II > IV
• C. III > I > IV > II
• D. IV > III > II > I

Answer 1

The correct option is A I > II > III > IV

The structures of the given compounds.

$\Rightarrow$ Chlorine is having high electronegativity so, it withdraw electrons from benzene rings.

$\Rightarrow$ Nitro group $\left({NO}_2\right)$ is also having electron with drawing property.

So, As the number nitro groups increases on chloro benzene the electron density is going to decrease on benzene. So, the order of decreasing electro density is as follows.

$I>II>III>IV$.