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
It was so exciting today in chemistry class because we went over the nomenclature for ketones, aldehydes, and carboxyclic acids!
We learned that a ketone is a hydrocarbon chain with a double bonded oxygen that is NOT on either end. In other words, it is an organic compound containing a C=O group at a position other than at the end of a hydrocarbon chain. The simplest ketone is propanone. As you can see, standard rules apply and we add -ONE to the parent chain.
We also learned that an aldehyde is a compound that has a double-bonded oxygen at the end of a chain. In other words, it is an organic compound containing a CHO group at the end of a hydrocarbon chain. The simplest aldehyde is methanal, which is also called formaldehyde. Again, standard rules apply and we change the parent chain ending to -AL. It's crucial that we don't confuse aldehydes with alcohols and ketones!
Finally, we looked at carboxylic acids. It is an organic compound that contains a COOH group. Carboxylic acids use standard rules but change the parent chain ending to -OIC ACID. The simplest carboxylic acid is methanoic acid. They are commonly referred to as "organic acids."
Methanoic acid
EXAMPLES:
KETONES
1.What is the structural formula for 4-octanone?
2.What is the structural formula for 3-hexanone?
3.Name the molecule shown below:
Cyclohexanone
ALDEHYDES
1.What is the structural formula for ethanal?
2.What is the structural formula for 2-methylpentanal?
3.Name the molecule shown below:
Benzaldehyde
CARBOXYLIC ACIDS
1.What is the structural formula for ethanoic acid (commonly called acetic acid)?
2.What is the structural formula for butanoic acid (commonly called butyric acid and is responsible for the odour of "smelly feet")?
3.Name the following carboxylic acid: CH3(CH2)4COOH.
Functional Groups are Organic Compounds containing elements other than Carbon and Hydrogen. Carbon chains without functional groups are written as R -, for example, R - OH.
There are nine functional groups:
1. Alcohols
2. Halides
3. Aderhydes
4. Ketones
5. Carboxylic Acids
6. Ethers
7. Amines
8. Amides
9. Esters
Alcohols
Alcohols are function organic molecules that contain the functional group OH. All Alcohols end in -ol.
Halides
Halides occur when one of the elements in Group 7 bond to a hydrocarbon chain. Naiming follows standard rules with halides using floro-, chloro-, bromo-, iodo-.
Ethers
Ethers are common organic compounds that contain an oxygen atom in the middle of two carbon chains. Oxygen is the parent chain.
Diethyl ether:
Ketones
Ketones are carbon compounds that contain a double bonded Oxygen atom. They have a -one ending and can't be on the first or last carbon.
Butanone:
Last class we had a quick test on everything we have learned so far in organic chemistry. Then we did a fun activity here we had to model compound structures that corresponded with compounds on a sheet given to us.
In today's class we learned how Carbon chains can form two different types of closed loops.
The above diagram is known as cyclopentane
-Alicyclics are loops that are usually made with single bonds.
When naming if the parent chain is a loop the standard naming rules apply, there is only one change and this is that one must add "cyclo-" in front of the parent chain
We also learned about a new, simpler way of drawing these organic compounds:
When numbering off an organic compound to find the lowest number for the side chains you can start anywhere in the circular shape. One can go clockwise or counter clockwise, which ever way that will give you the side chain numbers to be the lowest.
-Loops can be found in not only the parent chain, but also in the side chain, in this case the same naming rules apply but the side chain is given a "cyclo-" in front of it.
Aromatics
Benzene (C6H6) is a cyclic hydrocarbon with unique bonds between the carbon atoms.
Careful analysis allows us to see that all 6c-c bonds are identical and really represent a 1.5 bond
This is due to electron resonance and so the electrons are free to move around Benzene's interior ring.
Aromatic Nomenclature
A benzene molecule is given a special diagram to show its unique bond structure.
Carbon can form double and triple bonds with Carbon atoms. When multiple bonds form, fewer Hydrogens are attached to the carbon atom. Naming rules are almost the same as with alkanes.
The position of the double/triple bonds always has the lowest number and is put in front of the parent chain.
Double bonds (Alkenes) end in -ene. Triple bonds (Alkynes) end in -yne.
EX:
What is the name of this alkene?
What is the name of this alkyne?
Draw 3,3,4,4, tetramethyl 5,6 dimethyl 1 heptyne.
Trans and Cis Butene:
If two adjacent carbons are bonded by a double bond and have side chains on them two possible compounds are possible.
Multiple Double Bonds:
More than one double bond can exist in a molecule. Use the same multipliers inside the parent chain.
Organic Chemistry is the study of Carbon Compounds. Carbon forms multiple covalent bonds. Carbon compounds can form chains, rings, or branches. There are less than 100,000 non-organic compounds. Organic compounds number more than 17,000,000. The simplest organic compounds are made of carbon and hydrogen.
Carbons must always have 4 bonds.
Saturated compounds have no double or triple bonds. Compounds with only single bonds are called Alkanes and always end in -ane.
Nomenclature:
There are 3 categories of Organic compounds.
Straight chains
Cyclic Chains
Aromatics
Straight Chains:
Rules for naming straight chain compounds:
1. Circle the longest continued chain and name this and the base chain.(meth,eth,prop)
2. Number the base chain so side chains have the lowest possible numbers.
3. Name each side chain using the -yl ending.
4. Give each side chain the appropriate number. (If there
is more than one identical side chain numbers/labels are slightly different.)
The objective of this lab was to determine if Glycerin is Polar or Non-Polar.
To start the lab we set up 6 test tubes on a test tube rack. We then filled three test tubes a third full with water, and the next three test tubes a third full of paint thinner. We then added salt to a test tube filled with water and a test tube filled with paint thinner. We then proceeded to do the same with sugar iodine crystals.
After putting a stopper on each of the test tubes we inverted them one by one to see which substances dissolved. We observed that salt and sugar dissolved in water but the iodine crystals did not, and that in paint thinner the iodine crystals did dissolve while the salt and sugar did not. using these observations we learned than polar substances only dissolve if the solvent is polar and that non polar substances only dissolve if the solvent is non polar. To prove this more we mixed water after it had dissolved salt with paint thinner after it dissolved iodine. The result was the two substances not mixing and the paint thinner staying on top and the water staying on the bottom.
With our new found knowledge we mixed water with glycerin. Both being clear substances it was hard to see if glycerin was dissolved in water, but knowing that glycerin is polar and water is polar we know that glycerin did dissolve in water.
