Why are carboxylic acids stronger acids than alcohols?
Carboxylic acids are stronger acids than alcohols for two reasons:
- The carbonyl group connected to the -OH group draws electron density away from the O-H bond, making it easier to break.
- When the H+ ion dissociates, the resulting negative charge is delocalised over the whole of the carboxlyate group - this stabilises the carboxlyate ion and makes it easier for the acid to dissociate.
Answer in your head, out loud, or on paper, then tap the card to flip.
What are the names of the 2 carboxylic acids that can undergo further oxidation, and what is a suitable oxidising agent for this reaction?
Methanoic acid (HCOOH) and ethanedioic acid (HOOCCOOH) can be further oxidised to carbon dioxide by strong oxidising agents such as acidified potassium dichromate (KMnO4).
Methanoic acid can also be oxidised by Tollens' reagent, Fehling's solution, acidified K2Cr2O7 and acidified KMnO4.
Answer in your head, out loud, or on paper, then tap the card to flip.
State and explain the effect of chlorine substituents on the relative acidity of carboxylic acids.
Chlorine substituents increase the acidity of carboxylic acids.
Electron-withdrawing chlorine atoms weaken the O-H bond in the undissociated acid molecule and help to delocalise the negative charge across the carboxylate ion. This increases the stability of the carboxylate ion and makes it less likely to bond with an aqueous H+ ion.
Answer in your head, out loud, or on paper, then tap the card to flip.