Today was a review class - Uh oh! You know what that means! Dun! Dun! Dun!!!
We spent fifteen minutes taking up questions that people had. Then, we were given review handouts to complete in class as practice for the test. Be sure to review the following:
1. Nomenclature of Alkanes & Side Chains
2. Nomenclature of Alkenes & Alkynes
3. Alcohols, Aldehydes, Halides & Ketones
4. Carboxylic Acids & Esters
5. Amines & Amides
This is our final unit of Chemistry 11. All the best of luck!! "Don't fail!"
Last class we did an Esterfication Lab. The purpose of the lab was to synthesize an Ester from a carboxylic acid and an alcohol. To refresh our minds this is what an Esterfication reaction looks like:
The class was presented with three Ester's to synthesize; Methyl Salicylate, Isobutyl Methanoate, and Octyl Ethanoate. Most of the class chose Methyl Salicylate because it had a higher chance of producing a smell. To make Methyl Salicylate we added one scoop of Salicylic acid to a test tube. We then added roughly 15 drops of of methanol to the same test tube along with 3 drops of Sulphuric acid. The mixture was then placed in a hot water bath for 15 minutes with a beaker covering the test tube so as to allow gas to escape. After the hot water bath the mixture was placed in an ice water bath for 2 minutes. After the ice bath was completing we wafted the smell ad found that the newly formed Ester had a wintergreen smell, confirming the information we had received earlier. Though this version of making wintergreen is different than how our class did it, it still gives you an idea of what we did as it does contain similarities.
An "ester" is an organic, often fragrant compound formed in a reaction between an acid and alcohol with the elimination of water. In today's class, we learned all about these esters.
The COO group connects two hydrocarbon chains in an ester:
To name an ester:
The hydrocarbon chain attached directly to che carbon side of the COO group has its "e" ending changed to "-oate." The C in the COO group is considered to be part of the parent hydrocarbon chain.
The hydrocarbon chain attached to the oxygen side of the COO group is named as an alkyl group; the name of the alkyl group is used as a separate, initial word.
Esterfication:
Esterfication is the reaction of a carboxylic acid and an alcohol to form an ester and water! They are prepared by reacting in the presence of an inorganic acid (eg. HCl). The odour of an organic acid is a "sharp, pungent, and biting" smell. Alcohols also have a "sharp" odour. The smell of methanol and ethanol has very little odour but it tends to "catch" in the nasal passage. Propanol and higher alcohols have a very intense often unpleasant odours which also "catches" in the nasal passage. However, the odour of esters is generally very pleasant (fortunately). They form the basis of many fragrant fruit and flower smells! For example:
-Methyl butanoate: pineapple odour
-Pentyl ethanoate: banana odour
-Octyl ethanoate: orange rind
-Pentyl propanoate: apricot odour
-Ethyl methanoate: rum odour
As always, it's time for some examples!
1. What is the structural diagram for...
a)Methyl butanoate?
b)Butyl methanoate?
2. Name the following esters:
a)
Answer: Ethyl propanoate
b)
Answer: Propyl ethanoate
3. What esterfication forms the ester METHYL BUTANOATE? (Draw the structural diagrams)
Amines are functional groups that contain a Nitrogen compound bonded to either Hydrogens and Carbons.Also, amines are alphabetically named. There are three levels of Amines:
- Primary Amines have 1 carbon bond
- Secondary Amines have 2 carbon bonds
- Tertiary Amines have 3 carbon bonds
Amides must have a double bonded oxygen and an NH2. The endings for Amides are "-amide". One of the simplest amide is ethanamide.
Nitros have the funtional groupd of NO2. Also when naming a nitro, we add "Nitro" to the beginning of the
