a
Key ldea Higher the tendency to give a proton, higher is the acidic character and tendency to lose a proton depends upon the stability of intermediate,

i. e. carbanion formed.

\(2,4,6\) -trinitrophenol after the loss of a proton gives \(2,4,6\) -trinitrophenoxide ion which is stabilised by resonance, \(-l-\)effect and \(- M-\)effect, thus is most acidic among the given compounds.

Phenol after losing a proton form phenoxide ion which is also stabilised by resonance, \(- M\) and \(-I\) effects but is less stabilised as compared to

\(2,4,6\) -trinitrophenoxide ions. Thus, it is less acidic as compared to \(2,4,6\) -trinitrophenol. \(\left(C H_{3} C O O H\right)\) after losing a proton gives acetate

ion which is stabilised by only resonance. However, it is more resonance stabilised as compared to a phenoxide ion, thus more acidic as compared to phenol. \(2,4,6\) -trinitrophenol, however, is more acidic than acetic acid due to the presence of three

electron withdrawing \(-N O_{2}\) groups. Cyclohexanol gives an anion that is least stable among the given, thus, it is least acidic.

Hence, the correct order of acidic strength is

\(2,4,6\) -trinitrophenol > acetic acid > phenol > cyclohexanol

\(I I I>I I>I V>I\)