ORGANIC ACID BASES

The purpose of the organic acid is a weak acid is very incomplete because of ionization. At one time most of the acid in solution as molecules that are not ionized. For example, in the case etanoik acid, a solution containing 99% etanoik acid molecules and only 1 percent of that is really ionized. The position of the equilibrium being shifted to the left.
Why are acids acidic?
In any case, the bond between oxygen and oxygen-OH disconnected. So the only remaining molecule denoted as "X":
So if the same bond broken in any case, why the three examples above compounds produce acid level that is different?
 The difference between the acid strength of carboxylic acids, phenols and alcohols.
Factors to be considered
Two factors that affect the ionization of the acid is:
• The strength of the bond to be decided,
• the stability of the ions formed.
In this case, you break the bond of the same molecule (between O and H) so it can be determined bond strength is the same.
The most important factor in determining the relative strength of the molecule is in the nature of ion ion ion hidroksinium terbentuk.Anda always get so you do not need to compare it. All you need andabandingkan is the nature of the anions (negative ions) are different in each case.
Acid Etanoik
Etanoik acid has the structure:

Hydrogen is causing the acidic nature of hydrogen bound to oxygen. When etanoik ionized acid formed ethanoate ion, CH3COO-. You may think that the structure of the ethanoate ion is as below, but of the bond length measurements show that carbon with two oxygen bonds are the same length. With a length ranging from single bond length and bond ..
To identifies why, you have to look in detail ethanoate ionic bond.
Just like any other bonds, carbon-oxygen bond is in two distinct parts. A pair of electrons are found on the line between the two nuclei are called sigma bonds. Another pair of electrons are found above and below the plane in the form pi bond. The pi bond is made of p orbitals overlap between carbon and oxygen.
In ethanoate ion, one of the free electrons of oxygen are in a state negarif almost parallel to the orbit;-p orbitals and resulting overlap between oxygen atoms and the other carbon atom.
So there is delocalised pi system of whole-COO-but not as it did in benzene.
All free atoms of oxygen has been removed from the image to simpler.
Because hydrogen is more electronegative than carbon, so that electron delocalization occurs system longer is in the region of oxygen atoms.
Then where is the negative charge of the whole molecule? Jwabannya is spread among the entire molecule-COO-, but the most likely find it in the Sar between the two oxygen atoms.
The more you spread the load, the more stable the ion. Or in this case, if you mendelokalisasikan negative charge to a few atoms, the charge will be less attracted to the tendency to form hydrogen ions re etanoik acid was reduced.
Ethanoate ions can be described simply as:
The dotted lines represent the delocalization. The negative charge in the middle written to illustrate that the charge is not localized on one atom of oxygen.
Phenol
Phenol has an-OH group attached to the chain benzennya.

When the hydrogen-oxygen bond in phenol is lost, you get a phenoxide ion, C6H5O-.
Delocalization also occurs in this ion. At this time, one of the free electrons from the oxygen atom overlap with the electrons of the benzene chain.
This resulted dislokalisasi overlap. And as a result of not only the negative charge is on oxygen but scattered throughout the molecule.
Then why phenols are weaker than etanoik acid? In ethanoate ion, delocalization centered on the area between the two atoms are delocalized oksigen.Sistem divide between the two negatively charged oxygen atoms. There is no more powerful oxygen attract hydrogen ions.
In the phenoxide ion, single oxygen atom is still the most electronegative and delocalized system centered on the oxygen region. So that the oxygen atom has a charge of most negative, even though it does not have as much cargo if delocalization does not occur.
Delocalisation makes phenoxide ion is more stable than it should thus becomes acidic phenols. But not divide the charge delocalization effectively. The negative charge around the oxygen will be attracted to the hydrogen ion dam makes it easier phenol formation again. So that phenol acid is very weak.
Ethanol
Ethanol, CH3CH2OH, is a very weak acid up to the point that you can think of it not as sour. If the oxygen and hydrogen bonding disconnected and release of ions, ion etokside formed.
There is no way to mendelokalisasi negative for a strong bond with the oxygen atom. The negative charge will be very interesting and ethanol hydrogen atoms will be easily reformed.
 Variations in acid strength of some carboxylic acids.
You might think that all the carboxylic acids have the same power as it has the same delocalization around-COO-ion to make a more stable and not easily bound with hydrogen ions.
But the fact that there are a variety of carboxylic acids having acidity.
pKa
HCOOH 3.75
CH3COOH 4.76
CH3CH2COOH 4.87
CH3CH2CH2COOH 4.82
Keep in mind that the higher the pKa, the weaker the acid. Why etanoik acid weaker than adam metanoik? It all depends on the stability of the anion formed. Possible to mendislokalisasikan negative charge. Increasingly terdislokalisasi, the more stable the ion and the stronger the acid.
Ion metanoat metanoik acid:
The only difference between this and the ethanoate ion is the presence of the ethanoate CH3. Alkyl have tended to push electrons away so betambahnya negative charge on the-COO-. The addition of ionic charge makes more unstable because it makes it easier bound with hydrogen. So that etanoik acid weaker than metanoik acid.
Alkyl else also has the effect of "pushing electrons" as the methyl propanoic acid and that acid strength similar to butanoik etanoik acid.
Acid can be strengthened by drawing a charge from-COO-. Yanda can do this by adding electronegative atom such as chloride on a chain.
In the following table are shown the more you tie the more acidic chlorine molecules.
pKa
CH3COOH 4.76
CH2ClCOOH 2.86
CHCl2COOH 1:29
CCl3COOH 0.65
Amino acids Tmerupakan Trikloroetanoik strong enough.
Different halogen tie also makes a difference. Florin is the most electronegative atom so you can guess that the higher the level of acidity florins.
pKa
CH2FCOOH 2.66
CH2ClCOOH 2.86
CH2BrCOOH 2.90
CH2ICOOH 3:17
And the last note also the effects that occur with increasing halogen mnjauhnya of-COO-.
pKa
CH3CH2CH2COOH 4.82
CH3CH2CHClCOOH 2.84
CH3CHClCH2COOH 4:06
CH2ClCH2CH2COOH 4:52
Efektive chlorine atom adjacent to the current-COO-and the effect decreases as the chlorine atom away.
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ORGANIC BASES
This page describes a simple basic compounds and why their bases.
Why primary amines bases?
 Ammonia is a weak base
Many compounds containing ammonia and this time we will discuss the nature ddari ammonia.
For that, we define bases as "substance joins with hydrogen ions (protons)." We'll see how the bases take hydrogen ions dati water molecules when dissolved in water.
Ammonia in solution is in equilibrium as follows.
An ammonium ion is formed along with hydroxide ions. Since ammonia is a weak base, the state of the ion is not long and back again to its original state. Equilibrium shifts to the left.
Ammonia acts as a base because the lone pair of active nitrogen, nitrogen is more electronegative than hydrogen so attractive bonding electrons on the ammonia molecule at him. Or in other words the presence of a lone pair going negative charge around the nitrogen atom. The combination of these extra negativity and appeal lone pair, draw hydrogen from water.
Comparing the strength of the weak base
The strength of a weak base is scaled pKb. The smaller the value of this scale is a stronger base.
Three compounds will be seen along with their pKb values.
You can see that methylamine is a stronger base where phenylamine much weaker.
Methylamine is typical of primary aliphatic amines. Where NH2 attached to the carbon chain. All primary aliphatic Amin is a stronger base than ammonia.
Phenylamine is typical of primary aromatic amines - where the-NH2 group is attached directly to a benzene ring. These are very much weaker bases than ammonia.
 Explain the difference in the base
Things to think about
Two factors that affect the strength of a base is:
• Ease of lone pair binds hydrogen ions,
• the stability of the ions formed.
 Why aliphatic primary Amin is a stronger base than ammonia?
Methylamine
Methylamine has the structure:
The difference is the presence of ammonia in methyl amine CH3. The alkyl group has a tendency to mendoron electrons away from them. This will mean that a number of additional negative charge around the nitrogen atom. Additional negative charge is more interesting pairing free hydrogen atom.
The more negative nitrogen bound hydrogen ions more easily.
And what about the methyl ion current is established, whether it is more stable than the ammonium ion?
Compare methylammonium ions with ammonium ions.
Methylammonium ions, the positive charge of the ions scattered around effect "electron boost" methyl. The more you spread the charge, the more stable the ion. However, the ammonium ion is no way to spread the positive ions.
Summary:
• Nitrogen is more negative than in the ammonia methylamine, thus binding more active hydrogen.
• Ions are formed in methylamine is more stable than ions formed from ammonia, making it more difficult to change the form of hydrogen ions more ..
Conclusion: methylamine is a stronger base than ammonia.
Other aliphatic primary amines
Alkyl others have the effect of "electron boost" as methyl, so that the strength of aliphatic acids is very similar to another premises methylamine.
For example:
pKb
CH3NH2 3:36
CH3CH2NH2 3:27
CH3CH2CH2NH2 3:16
CH3CH2CH2CH2NH2 3:39
 Why aromatic primary amines are weaker bases than ammonia?
Aromatic primary amines are compounds in which-NH2 group is attached directly to a benzene ring. That might be you often encounter is phenylamine.
Phenylamine has the structure:
Nitrogen lone pair of electrons delocalized ring touching .....
. . . and become delocalized along.
This means that couples no longer fully free to join the hydrogen ions. Nitrogen is still the most electronegative atom in the molecule and therefore approaching the delocalisation going in that direction, but the intensity of the charge around the nitrogen is not such as in within the molecule.