Organic Functional Groups. Functional Gps vs. Chemistry Department. Simple Inorganics. Organic Chain Length. Virtual ChemBook. Polarity of Organic Compounds Principles of Polarity: The greater the electronegativity difference between atoms in a bond, the more polar the bond. Organic Functional Group Polarity and Electrostatic Potential: The molecular electrostatic potential is the potential energy of a proton at a particular location near a molecule.
Boiling Point Definition: In a liquid the molecules are packed closely together with many random movements possible as molecules slip past each other.
Polarity and Boiling Point: The polarity of the molecules determines the forces of attraction between the molecules in the liquid state. Functional Group Ranking by Boiling Points.
Functional Group Name. Boiling Point. Polar Rank most to least. Brief Explanation. On the other hand, their boiling points are considerable higher than the ether or alkane, indicating the presence of weak intermolecular dipole-dipole forces.
The carbonyl group "carbon double bond oxygen" is polar since oxygen is more electronegative than carbon and forms a partially charged dipole. The nitrogen in the amine is much less electronegative than oxygen in the alcohol. And if I think about the carboxylic acid, from which this is derived, so you have to use your imagination a little bit, so if I think about this portion, instead of the nitrogen here, if I had an OH, that would be benzoic acid. So I'm just gonna go ahead, and write that right here.
So, "benzoic acid. So it has our parent name here, so we would have "benzamide" here. And then, let's think about what else we have: we have a nitrogen, and we have a methyl group, one methyl group bonded to that nitrogen, and then we have another methyl group over here on the ring. So let's go ahead, and number the ring, and see where our other methyl group is. So our other methyl group, if we number our ring, this would be carbon one, if we think about this as being like benzoic acid.
So if we're numbering our ring, this would be carbon one, and then carbon two, carbon three, and carbon four. So we have a methyl group at carbon four, and we also have a methyl group coming off of our nitrogen. So this time, we're going to write, let me go ahead and write here, this'll be "N, 4-dimethyl," so we have "N, 4-dimethyl-benzamide," as our name for this molecule.
So, notice the difference. So here we have a methyl group, on our nitrogen, right here, and we have a methyl group coming off of carbon four, so that's where our dimethyl comes from. For this one, we have N, and another N, because both of our methyl groups are coming off of the nitrogen in the example on the left, and so it's just useful to contrast these two molecules, when we're thinking about nomenclature.
In terms of physical properties of amides, let's look at a little diagram here, showing acetamide. So we have our amide right here, and physical properties, in terms of what state of matter is this, acetamide is actually a solid, at room temperature and pressure, and so this is a solid.
It has a lot of hydrogen bonding: so, we could think about some hydrogen bonding here, we could think about some hydrogen bonding here; there are lots of opportunities for hydrogen bonding. So partial negative oxygen, partial positive hydrogen, bonded to this nitrogen, which is withdrawing some electron density from this hydrogen. So, lots of opportunities for hydrogen bonding.
Acetamide is solid at room temperature, and so its melting point turns out to be, approximately 82 degrees Celsius, so that's its melting point; its boiling point is actually much higher, so, somewhere around degrees, so higher.
This is actually the melting point, and the boiling point being much higher, due to the very strong inter-molecular forces that are present between amide molecules. In terms of solubility of amides in water, small amides are definitely soluble. So if I think about water coming along. Let's go ahead a draw water in here. Which functional group is more polar in a drug: primary amide or a carboxylic acid?
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Gaurang Tandon 8, 10 10 gold badges 55 55 silver badges bronze badges. Michael Nguyen Michael Nguyen 1 1 gold badge 4 4 silver badges 11 11 bronze badges. That might or might not; I don't know affect the conclusion you draw. I think the negative charge at physiological pH is your only real chance of a definite indicator.
Did you perhaps mean to compare a carboxylic acid to a primary amine, not an amide? Just curious. Add a comment. Active Oldest Votes. Improve this answer. KG3 KG3 1 1 silver badge 11 11 bronze badges. Tom Oldani Tom Oldani 1.
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