Which of the following reactions is used to obtain salicylic acid from phenol?

$A$ compound $x$ reacts with Bromine water and gives a white precipitate. If compound $x$ reacts with $Zn$ dust and forms benzene,then $x$ is:

The major product in Reimer-Tiemann reaction is $X$. The reactants are $Y$ and $Z$. $X$,$Y$ and $Z$ are respectively.

An organic compound $(C_8H_{10}O_2)$ rotates plane-polarized light. It produces a pink color with a neutral $FeCl_3$ solution. What is the total number of all the possible isomers for this compound?

Among the following four compounds:
$(i)$ Phenol
$(ii)$ Methyl phenol
$(iii)$ Meta-nitrophenol
$(iv)$ Para-nitrophenol
The acidity order is:

Rank the following compounds in order of decreasing acid strength (most acidic $\to$ least acidic):