Which of the following compounds decolourises $Br_2 / H_2O$ and also gives a positive test with neutral $FeCl_3$?

Arrange the following compounds in the increasing order of their acidic strength :
$i$. $m-$nitrophenol
$ii$. $m-$cresol
$iii$. phenol
$iv$. $m-$chlorophenol

Among the following,which is least acidic?

In the Liebermann’s nitroso reaction,the changes in the colour of phenol occur as:

What is the increasing order of acidic strength among the following?
$(i)$ $p-$methoxy phenol
$(ii)$ $p-$methyl phenol
$(iii)$ $p-$nitro phenol

Phenol on heating with $CHCl_3$ and $NaOH$ gives salicylaldehyde. The reaction is called