Which of the following substances will increase the acidity of phenol?

Which one of the following compounds will readily react with dilute $NaOH$?

The reactant is $4-hydroxy-3-methylbenzenesulfonic acid$. The reaction with $Br_2$ in $H_2O$ (bromine water) is an electrophilic aromatic substitution. The $-OH$ group is strongly activating and ortho/para directing. The $-SO_3H$ group is a good leaving group in the presence of excess bromine water. Predict the product of the reaction: $\xrightarrow{Br_2, H_2O} \text{Product}$

Product $(Q)$ in this reaction is

Which of the following substituted phenols is the strongest acid?

When phenol is treated with $PCl_5$,the yield of chlorobenzene is generally poor because of the formation of