2007-08-19 15:49:51 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
Catbarf had a nice explanation but I think even more importantly the reason why a carboxylic acid is more acidic than an amide is because oxygen is more electronegative than nitrogen and can therefore more readily accommodate the negative charge. Hope this helps.
2007-08-19 16:13:38 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Hi... This has two bases. First of all, the more electronegative the atom binded to the carbon, the more acidic it is. Across any row in a periodic table, the electronegativity increases, and down a group/family, decreases. We can see that the nitrogen of amides is less electronegative than that of the oxygen bonded to a carboxylic acid. By the way, an amide is only weakly basic because it is resonance stabilized; that is why it possesses acidic properties. The more stabilized a structure is by resonance, the more acidic it is. The actual structure in an amide and a carboxylic acid that makes it resonance stabilized is the double-bonded oxygen. (Resonance stabilization is also called pi electron delocalization, meaning there is a pi bond; in a double bond or triple bond).
Let us move on to the second basis then. Now, there are effects called inductive effects that are electron-widthrawing (attracting) and electron-releasing (repelling). If group is electron-widthrawing, it is more acidic, but if group is electron-releasing, it is more basic/less acidic. The nitrogen of amides is an electron-releasing group, because according to the Lewis definition of bases, it has a lone pair that it can share. If you can remember the nitrogen of amides, it has a single lone pair on top when drawn.
And by the way, by evidence, carboxylic acids are the strongest organic acids so it folows that an amide is less acidic than a carboxylic acid.
Hope that helps. =)
2007-08-19 20:24:35 · answer #2 · answered by Eloise 2 · 0⤊ 0⤋
A carboxylic acid has a COOH structure, where the first oxygen is double-bonded to the carbon and the -OH group is also bonded to the carbon. The H+ comes from the -OH group, leaving a -COO- ion behind. The two oxygens can stabilize the negative charge by what is known as resonance. This lowers the energy of the ion. Amides don't have this capability.
2007-08-19 16:04:36 · answer #3 · answered by cattbarf 7 · 1⤊ 0⤋
Amides are the product from a reaction between a carboxylic acid and an amine. Therefore their acidity is somewhat less than the acid and somewhat more than the amine.
2007-08-19 15:59:34 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Amides are the most unreactive of all carboxylic acid derivatives. This is because of its slight double bond characteristic that reduces the leaving group ability of the nitrogen. This resonance form is more prevalent among amides than it is for carboxylic acids, esters, or anhydrides.
2017-01-13 07:13:12 · answer #5 · answered by Harsh 1 · 0⤊ 0⤋
well amindes are molecules with NH3 attached to them and they are not acidic because they are not acids (means they do not comtain lots of hydrogens==== always remember the more hydrogens found in a substance the most acidic it is=means lower pH levels). Carboxylic acids are more acidic as they contain more Hydrogen atoms and hence the name (acids) but they are weak acids (depends on their types and their locations and of course their molacular stuctures.
2007-08-19 16:00:40 · answer #6 · answered by Heba A 3 · 0⤊ 0⤋
amides do not readily give their hydrogens as they are bounded to the nitrogen whereas the hydroxy' group on the carboxylic acid group readily disassociates as pH changes
2007-08-19 15:55:26 · answer #7 · answered by aevus 2 · 1⤊ 0⤋