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Ketones Lab Report

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The Carbonyl group, found on the ketone, is a polar group due to the oxygen atom being more electronegative than the carbon atom. This creates a molecule that is slightly polar. It is a relatively stable molecule with a relatively high boiling point. All three Ketones on the table have a boiling point close to water or substantially higher. The carbon atom in the carbonyl group is not electronegative enough to give a partial charge large enough for hydrogen bonding to the hydrogen atoms in Pentanone.

Butanoic Acid, however, has a much higher boiling point than all three ketones. Butanoic acid does not have the highest molecular mass. This phenomenon can be attributed to hydrogen bonding. Due to the way the carboxylic molecule is arranged, …show more content…

>C=0 attractions as well as hydrogen bonding since there are two sites on the molecule for hydrogen bonding, dimers are readily formed for the lower members of the series. Although each interaction is minute, collectively, even the weakest of intermolecular forces can add up to give an impressive effect. We can see in the table above that even though Butanoic acid has a very similar molecular mass to Pentanone, it's boiling point is more than 60 degrees higher. is significantly stronger than an ordinary dipole-dipole interaction.Hydrogen bonds have about a tenth of the strength of an average covalent bond, and are being constantly broken and reformed in liquid …show more content…

This resonance creates stability. The distribution of the negative charge on the carboxylate ion increases stability because the charges are divided. Each oxygen bears a charge of negative 1/2. This reduction in charge concentration increases stability. Furthermore, two molecules of a carboxylic acid creates two hydrogen bonds. They exist as ' dimers' or pairs. In the liquid state and sometimes in the vapour state these dimmers remain in tact. In effect, the molecular weight is doubled when dimmers exists in vapours. extra energy is required to break two hydrogen bonds. In actual fact, many carboxylic acids ( ie benzoic, palmitic acid) are solids at room

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