Question

Arrange the following in decreasing order of their acidic character:
(i) ${CH}_3-O-C_6{H}_{4}OH$
(ii) $C_6{H}_5-OH$
(iii) ${NO}_2-C_6{H}_{4}OH$

Answer 1

Addition of a +R group $(-OC{H}_3)$ to the the benzene ring in phenol reduces its acidic property while addition of a -R group $(-N{O}_2)$ to the same phenol ring increases its acidic character.
Hence, the correct sequence in decreasing order of acidity is
$\left(iii\right)>\left(ii\right)>\left(i\right)$