The major product of the following reaction is:

What is the correct order of acidity for the following compounds?

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

The ascending order of acidity of the $-OH$ group in the following compounds is:
$A$. $Bu-OH$
$B$. $p$-nitrophenol
$C$. $p$-methoxyphenol
$D$. Phenol
$E$. $2,4$-dinitrophenol
Choose the correct answer from the options given below:

Which of the following does not give effervescence with $NaHCO_3$?

Cumene on oxidation in air gives a compound,$X$. This on reaction with dilute acid gives $Y$ and $Z$. $Y$ reacts with sodium metal and not $Z$. What is $Z$ ?