The decreasing order of acidity of the follow | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) The acidity of terminal acetylenes depends on the stability of the conjugate base (carbanion) formed after the removal of the acidic proton. Elect

Vedclass · Accepted Answer

$(i) > (ii) > (iv) > (iii)$

Vedclass · Answer

(B) The acidity of terminal acetylenes depends on the stability of the conjugate base (carbanion) formed after the removal of the acidic proton. Electron-withdrawing groups $(EWG)$ stabilize the carbanion through $-R$ or $-I$ effects,thereby increasing acidity. Electron-donating groups $(EDG)$ destabilize the carbanion through $+R$ or $+I$ effects,thereby decreasing acidity. In the given compounds: $(i)$ has a $-CO_2Et$ group,which is a strong $EWG$ ($-R$ effect),making it the most acidic. $(ii)$ is phenylacetylene with no substituent. $(iv)$ has a $-CH_3$ group,which is an $EDG$ ($+I$ effect),making it less acidic than $(ii)$. $(iii)$ has a $-OCH_3$ group,which is a strong $EDG$ ($+R$ effect),making it the least acidic. Thus,the decreasing order of acidity is $(i) > (ii) > (iv) > (iii)$.

The decreasing order of acidity of the following terminal acetylenes is:

Similar Questions

Identify ortho and para directing groups from the following: $I. -CHO$,$II. -NHCOCH_3$,$III. -OCH_3$,$IV. -SO_3H$.

Select the correct set of substituents for the existence of $-M$ and negative inductive $(-I)$ effects.

Classify the following groups as electron-withdrawing ($-I$ effect) or electron-donating ($+I$ effect) inductive effect groups: $-CH_3, -Cl, -NO_2, -(CH_3)_3C, -OC_6H_5, -C_6H_5, -OH, -NH_2, -CH_2CH_3$.

The correct order of the electron-donating or withdrawing effect (inductive/mesomeric effect) for the groups $-NH_2, -OCH_3, -C_6H_5$,and $-NO_2$ is:

Identify the most acidic hydrogen present in the given compound.

Vedclass Test Series

Exam Paper Generator

Online Exam Module