Question

Phenol does not decompose $NaHC{O}_3$ to evolve but picric acid does.
A.True
B.False

Answer 1

Hint: Acids react with sodium hydrogen carbonate to evolve carbon dioxide. The compounds which are more acidic than carbonic acid will react with $$NaHC{O}_3$$ else the reaction would not take place.

Complete Step by step answer: Phenol is acidic in nature . But it is a weak acid. The presence of $-OH$ on phenol and the conjugation of electrons in benzene rings pull the electrons away from the $-OH$ group . Sodium bicarbonate is a weak base . It easily accepts electrons from stronger acids like carbonic acid, but it is not strong enough to pull the proton off phenol. Hence, due to the weak acidic nature of phenol $$NaHC{O}_3$$ does not react with phenol .
We will see whether it reacts with picric acid or not.
$2,4,6-trinitrophenol$ is commonly known as picric acid.
The presence of three nitro groups at ortho-para positions increases the acidity of the compound. It is an electron withdrawing group . EWG ( electron withdrawing group ) increases the acidic character of any compound. And hence picric acid becomes a stronger acid than phenol and carbonic acid. It is actually as strong as hydrochloric acid. Since any acid stronger than carbonic acid can react with $NaHC{O}_3$ and give effervescence of $C{O}_2$.
Hence, picric acid reacts with sodium bicarbonate to give effervescence of carbon dioxide while phenol does not.

The correct option A is TRUE.

Note: This can be seen as a general reaction between an acid and a base. Only the acids that can readily donate protons can react with it. Phenol is less acidic than both picric acid as well as carbonic acid.