Why pKa of ethanoic acid is higher than that of methanoic acid?

The less the charge is delocalised, the less stable the ion, and the weaker the acid. Any build-up of charge will make the ion less stable, and more attractive to hydrogen ions. Ethanoic acid is therefore weaker than methanoic acid, because it will re-form more easily from its ions.

Why is the boiling point of ethanoic acid higher than methanoic acid?

For acetic acid, H3C−C(=O)OH , hydrogen-bonding operates, the which is a potent intermolecular force, such that its boiling point is 118 ∘C this is very high for an organic molecule of such short length.

How is ethanoic acid different from methanoic acid?

Methanoic acid and ethanoic acid are the simplest forms of carboxylic acids. The difference between methanoic acid and ethanoic acid is that methanoic acid consists of a hydrogen atom bonded to a carboxylic functional group whereas ethanoic acid consists of a methyl group bonded to a carboxylic acid group.

What is the pKa of methanoic acid?

For which the acid dissociation constant is: This allows us to have a pKa value for a specified base, although it is actually the pKa value of the conjugate acid of the base. The following relationships exist: pKa + pKb = 14….

Acid	pKa
Methanoic acid	3.75
Ethanoic acid	4.76
Propanoic acid	4.87
Butanoic acid	4.82

Why ethanoic acid is less volatile than water?

Ethanoic acid, like other carboxylic acids, is able to form dimers. Since the two molecules form hydrogen bonds with each other, they no longer are so attracted to chains of water molecules or other carboxylic acid molecules and may more easily escape to the gaseous phase.

Why does ethanoic acid have a higher boiling point than butane?

In a pure carboxylic acid, hydrogen bonding can occur between two molecules of acid to produce a dimer. This immediately doubles the size of the molecule and so increases the van der Waals dispersion forces between one of these dimers and its neighbours – resulting in a high boiling point.

Which is stronger ethanoic acid or methanoic acid?

The less the charge is delocalised, the less stable the ion, and the weaker the acid. Ethanoic acid is therefore weaker than methanoic acid, because it will re-form more easily from its ions.

Which test is used to distinguish between methanoic acid and ethanoic acid?

So, tollen’s reagent i.e. ammoniacal silver nitrate solution can be used to differentiate between methanoic acid and ethanoic acid. Tollen’s reagent can be reduced by methanoic acid but it is not reduced by ethanoic acid.

Why does methanoic acid have a lower pKa than methanol?

Therefore, pKa for methanoic acid is lower than that for ethanoic acid. the methyl carbon attached in methanol is not easily ionised compared to ethyl group . In methanoic acid there is only one hydrogen attached to carboxyl group while in ethanoic acid methyl is attached to the carboxyl group.