Ketones, Aldehydes, & Carboxylic Acids!

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.



Hexanoic acid


Check out this cool youtube video:

Alcohols & Halides!

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:

Propanone (acetone):

Model Molecular Structures!

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.

Alicyclics and Aromatics!

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.

Benzene can be found as a parent or a side chain

When a side chain it is given the name "Phenyl."

Alkenes and Alkynes: Double and Triple Bonds

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.

Introduction to Organic Chemistry & Alkanes!

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.)

5. List side chains alphabetically.

EX:

Name The Alkane:

Draw The Structural Diagram for Hexane:

TEST: BONDING

Today we had our BONDING unit test. All went well.

Topics covered:

• Bonds & Electronegativity
• Polar Covalent Bonds
• Polar Molecules
• Types of Intermolecular Bonds
• Effects of Intermolecular Bonds on Molecules

We look forward to our next, and final unit: ORGANIC CHEMISTRY!

Polar and Non-Polar Solvents Lab

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.

The polar chemical structure of glycerin:

Intramolecular and Intermolecular Bonds!!

In todays class we learned about Intramolecular and Intermolecular Bonds!! But before we start here is something to ponder over.

Here are the types of bonds:

Intramolecular bonds exist within a molecule.

-Covalent, Ionic

Intermolecular bonds exist between molecules.

-The stronger the molecular bond the higher the melting point and boiling point are.

-two types of intermolecular bonds are:

1. Van der Waals bonds

2. Hydrogen bonds

-they are based on electron distribution

-There are two categories that they can fall under:

1. Dipole-Dipole bonds

- if a molecule is polar the positive end of one molecule will be attracted to the negative end of the other molecule.

2. London Dispersion Forces (LDF)

-LDF is present in all molecules

-creates the weakest bonds

-A non polar Dipole-Dipole forces do not exist

-Electrons are free to move around and at some point may be at one side of the atom which leaves an open area to form a temporary dipole. This would form a weak bond on that open side.

-The more the molecules in a bond the stronger the LDF can be.

Hydrogen Bonding

-Hydrogen is bonded to certain elements [ (N)itrogen, (O)xygen, (F)lourine. ] where the bond is highly polar.

-this is a very strong intermolecular bond.

Here is a video explaining this topic, Enjoy!

Polar Molecules

Polar molecules have an overall charge separation. Unsymmetrical molecules are usually polar.



Molecular dipoles are the result of unequal sharing of electrons in a molecule.

Water bending is a good example of this.



Predicting Polarity

If a molecule is symmetrical the pull of e- is usually balanced. Molecules can be un-symmetrical in two ways:

-different atoms
-different numbers of atoms

Example: Find Polarity



Right now we are not too concerned about the shape of molecules but if we were we could use the VSPER method to figure the shapes out.