Which is more acidic para fluoro benzoic acid or para chloro benzoic acid?

First, it is true that para-chlorobenzoic acid is more acidic (pKa=3.98) than para-fluorobenzoic acid (pKa=4.14). Based on inductive effects (aka I-effect), fluorobenzoic acid should be more acidic as ‘F’ is more electronegative than ‘Cl’. The other consideration is resonance.

Why ortho methyl benzoic acid is more acidic than para fluoro benzoic acid?

Can you please explain me why Ortho methyle benzoic acid is more acidic than para fluro benzoic acid? Answer: In the case of O-methyl benzoic acid, the methyl group attached to the benzene ring is stabilized the conjugate base formed. Therefore, ortho methyl benzoic acid is more acidic than para fluoro benzoic acid.

Which is more acidic benzoic acid or chloro benzoic acid?

-COOH is meta directing group and hence it isn’t stabilised at the para position. Hence benzoic acid is more acidic than para-chloro benzoic acid(because the resonating structure of benzoic acid is more stable than p-chloro benzoic acid due to the reason mentioned above).

Which is more acidic para methyl benzoic acid or para chloro phenol?

It is benzoic acid which is more acidic of the two. In P- chloro phenol the electron withdawing chloro group would also tend to polarise the O-H bond of hydroxyl group.. An acid whose conjugate base is more stable is a stronger acid…

Which chlorobenzoic acid is more acidic?

Meta-chlorobenzoic acid is around 1.05 times more acidic than para-chlorobenzoic acid. In m-chlorobenzoic acid, the electronegative chlorine atom pulls some of the electron density towards itself.

Which is more acidic fluorobenzene or chlorobenzene?

Therefore, with longer C-Cl bond providing more polarity, but less inductive pull and less resonance push, chlorobenzene is likely to be more polar than fluorobenzene and therefore Ph-Cl has slightly higher DM than Ph-F.

Why Ortho benzoic acid is more acidic than para benzoic acid?

The intramolecular hydrogen bond in ortho-hydroxybenzoic acid between the COO− and the -OH groups forms a six membered ring. Since this structure is very stable, the deprotonation of the acid is favoured and the compound is more acidic.

Why is meta-chlorobenzoic acid more acidic than para-chlorobenzoic acid?

The chlorobenzoate ion is stabilised by the electron-withdrawing group. In m-chlorobenzoate ion, the electron-withdrawing chlorine atom is nearer to the carboxylate group, hence, the stronger electron-withdrawing effect. It’s more easily for m-chlorobenzoic acid to donate proton. So, it’s a stronger acid.

Why is meta methyl benzoic acid more acidic than para methyl benzoic acid?

The methyl group at ortho & para-position(4-position) destabilises Negative charge of corresponding Carboxylate ion both +I (Inductive ERG)) as well as by +H (hyperconjugation). Hence m-isomer is more acidic than para-isomer.

Which is more acidic or methyl benzoic acid or para methyl benzoic acid?

The ortho effect is responsible for ortho methyl benzoic acid to be more acidic than para methyl benzoic acid. In a general trend, ortho substituted acids are stronger than their counterparts. Similarly, ortho substituted bases are weaker than their counterparts.

Is p -chlorobenzoic acid more or less acidic than P -fluorobenzosic acid?

However, in reality, p -chlorobenzoic acid is less acidic than p -fluorobenzoic acid . Why? p K a of para chlorobenzoic acid ⟶ 4.03. Source p K a of para fluorobenzoic acid ⟶ 4.14. Source For acidity of para substituted benzoic acids, -I effect is helpful and +R effect decreases the acidity.

Why is para methoxy benzoic acid less acidic than benzoate?

Para methoxy benzoic acid is less acidic due to the presence of EDG, +M effect by lone pair of electrons. It decreases the stability of benzoate ion after the release of H+ ion. Lower the stability of Conjugate Base, lower will be the acidic strength.

What is the -I and +R effect in benzoic acid?

For acidity of para substituted benzoic acids, -I effect is helpful and +R effect decreases the acidity. In 4-fluorobenzoic acid, the +R effect is prominent in F due to stronger 2 p π − 2 p π overlap with nearest carbon.

Why does a starred carbon have a negative charge in 4-fluorobenzoic acid?

In 4-fluorobenzoic acid, the +R effect is prominent in F due to stronger 2 p π − 2 p π overlap with nearest carbon. Thus, due to stronger +R effect of F than -I effect, it creates a negative charge on your starred carbon.