Which of the following reagents can be used to distinguish between phenol and ethanoic acid?

Compound $A$ $(C_7H_8O)$ is insoluble in water,dilute $HCl$,and aqueous $NaHCO_3$,but it dissolves in dilute $NaOH$. When $A$ is treated with $Br_2$ water,it is converted into a compound $C_7H_5OBr_3$ rapidly. The structure of $A$ is

Carbolic acid is oxidised by acidified sodium dichromate to give

What is $X$ in the given reaction?

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

Which statement is incorrect for the product of the reaction shown above?