What is the $IUPAC$ name of picric acid?

Assertion : Reimer-Tiemann reaction of phenol with $CCl_4$ in $NaOH$ at $340 \ K$ gives salicylic acid as the major product. Reason : The reaction occurs through intermediate formation of dichlorocarbene.

In the Liebermann nitroso reaction,what is the sequence of color changes observed in phenol?

The reaction sequence is as follows:
$Catechol \xrightarrow{(i) CHCl_3 + KOH}{(ii) CH_2I_2 + NaOH} [X]$
Here $[X]$ is:

Phenol reacts with acetone in the presence of concentrated sulphuric acid to form a $C_{15}H_{16}O_2$ product. Which of the following compounds is this product?

Phenol is treated with bromine water and shaken well. The white precipitate formed during the process is