Organic Chemistry

Organic chemistry is the chemistry of carbon compounds. It is responsible for many of the every day products that are used around the world.
Some examples:

• clothing
• all plastics

Properties of organic compounds

• low melting points
• weak or non-electrolytes
• can form chains of carbon atoms that are linked in a 
• Straight line
• circular pattern
• branched pattern
• can link with other atoms in a

Alkanes (unbranched/straight chain) 

A hydrocarbon is a compound that contains only hydrogen and carbon; there are diff. types of hydrocarbons, and diff. ways to represent them.

Alkanes are saturated hydrocarbons which have carbon atoms bonded by single bonds

-saturate: not possible for another atom to bond to the structure

Naming an alkane is pretty simple. The names of hydrocarbons end in "-ane" because they are alk-ANE-s. 

Here's a video on naming the first 10 alkanes

The First 10 Alkanes

Alkyl Groups

-these are alkanes that have lost one hydrogen atom

if there are more than one of the same kind of alkyl group, use the prefix "di", "tri", "tetra" etc. 

Organic Chemistry

Functional Groups

Functional Groups are organic compounds that can contain elements other than Carbon and Hydrogen.
A functional group may be a single atom (such as F, Cl, Br, or I), or groups of atoms (such as NO2, NH2).
There are 4 types of functional groups.

• Alcohols
• Halides (halogen) or Nitro
• Aldehydes
• Ketones

Halides and Nitro Compounds

Halogen and Nitro compounds can be attached to all alkanes, alkenes, and alkynes. 

The main chain name will receive one of the following prefixes if the appropriate group is attached.

Fluorine -> Fluoro

Chlorine -> Chloro 

Bromine -> Bromo

Iodine -> Iodo

...and so on. As you can see you just replace the "-ine" with "-o". 

Properties of Halogenated Compounds

1. Compounds containing F, Cl, Br, and I are generally insoluble in water.
2. Fluorinated hydrocarbons are unreactive.
3. Compounds containing Cl or Br are more reactive, but only in drastic conditions.
4. Compounds containing I are extremely reactive. 

Properties of Nitro Compounds 

1. Normally insoluble in water.
2. Unreactive to chemical attack, except under drastic conditions.
3. Tend to be explosive.
4. Generally have a pleasant odor. 

Alcohol

Alcohol is an organic compound that contains an -OH (hydroxyl) functional group. 

Alcohols are named by using the longest carbon chain containing the OH group, and replacing the "-E" ending in the parent hydrocarbon chain with the ending "-OL".

Properties of Alcohols

1. Soluble in water, but hydrocarbon chain tends to be insoluble in water.
2. All alcohols are poisonous in some degree. 

What happens if there's more than one OH? 

If a compound has more than one -OH group, number both and add the prefix ending. "-diol", "-triol", etc. 

Check out this video that sort of explains alcohols in a catchy rap.
Alcohol Rap

Aldehydes 

An Aldehyde is a compound that has a double bonded oxygen at the end of a chain. 

Change the parent chain ending to "-al". Be careful! Don't confuse this with alcohol! 

Here's a quick video on aldehydes.

Aldehydes

Ketones

Ketones are hydrocarbon chains with double bonded oxygen that is NOT on either end.

Add "-one" to the parent chain.

Properties of Aldehydes and Ketones

1. Both partially soluble in water.
2. Aldehydes are very reactive.
3. Ketones are relatively unreactive. 

Here's another video, this time on Ketones 

And finally, the last video I'm going to show you is a video on ALL functional groups!

Functional Groups

Bonding

There are 3 types of chemical bonds

Ionic bonds: the transfer between 2 atoms to form a positive and negative ion.
Non-polar covalent bonds: equal sharing of electrons
Polar covalent bonding: unequal sharing of electrons



Ionic bonding uses an electrostatic force. That is the force that exists between particles that are charged as a result of attraction or replusion. (remember, opposites attract? Opposite charges attract and like charges repel). These bonds are very strong and have a high melting temperature.

So, I know you guys have a burning question:

Why do things lose valence electrons? This is explained by electronegativity. Metals have low electronegativity and non-metals have high electronegativity, as we learned in the last chapter. The electronegativity decreases to the right across the periodic table. The difference in the electronegativity will determine the electron sharing and determine if it is equally shared or unequally shared.

Here is how to figure that out! This is the formula:

ENeg Diff.= [ENeg1 - ENeg 2]

If it is a non polar covalent bond, the difference will be <0.5
If it is a polar covalent bond, the difference will be >0.5 and <1.8
If it is an ionic bond, the difference is >1.8


If ENeg Diff <0.5 it's a non polar covalent bond

If ENeg Diff > 0.5 and <1.8 it's a polar covalent bond

If ENeg Diff > 1.8 it's an ionic bond




Lets try an example:

Arsenic and Sulfur
Arsenic is 2.18 and Sulfur is 2.58. |2.18-2.58| = 0.40, therefore it is covalent.

Cobalt and Bromine
Cobalt is 1.88 and Bromine is 2.96 |1.88-2.96| = 1.08, therefore it is a polar covalent bond./

To draw diagrams of the compounds, draw the central atom in the middle and distribute the remaining atoms around it. Draw arrows indicating the direction of the polarity. Draw the partial positive and partial negative charges.

Partial Positive sign is the almost 8 but cut-off sign with a +
Partial Negative sign is the same thing but with a -


What is polarity?
Different Kinds of Bonds

Alkenes and Alkynes

Here are some basic facts:

-Carbon can form double and triple bonds with Carbon atoms
-When multiple bonds from fewer hydrogens are attached to the carbon atom

Alkenes

Alkenes are simply hydrocarbons with one or more double bonds located between carbon atoms leading to an "unsaturated hydrocarbon."

For example: CH2 = CH2 Ethene

CH2 = CH - CH3             1-propene or propene

                                                                            Ethene

Naming Rules:

1) Find the longest chain and place it at the end of the name

2) Number the carbon atoms to get the lowest number for the start of the double bond and place that number before the parent name

3) Assign names and numbers for all side groups and assemble the name alphabetically

Difference between cis and trans:

Cis = both on top or bottom

Trans = one on top and one on bottom



Alkynes

Alkynes are simply hydrocarbons with one or more triple bonds located between carbon atoms leading to an "unsaturated" hydrocarbon

The ending is changed from one of the alkanes and alkene for alkenes to "yne" for alkynes

Same naming/drawing rules apply!

Still feeling confused? Here are some helpful videos:

Naming Alkenes

Naming and Drawing Alkynes

Naming AND drawing Alkenes (25 minutes long!)



Predicting the Number of Valence Electrons

Valence Electrons are the electrons in the outermost (energy level) open electron shell of an atom.
They are the electrons that can take part in chemical reactions, also called the "reactable electrons".
Some things you may need to know:
Open Shell: A shell that contains less than its maximum number of electrons
Closed Shell: A shell that contains exactly its maximum number of electrons.

All Noble Gases have 0 valence electrons, because they all have something called a stable octet.
A stable octet is when the shell has exactly 8 electrons on it.

example: Neon.
Atomic number: 10.
We all think back to grade 10, and remember the order of the number of electrons each shell can hold.
First shell holds 2 electrons.
Second shell holds 8.
Third shell holds 8.
Fourth (and final) shell holds 16.

As you can see, there is a perfect shell - or a stable octet. There is no room for any more electrons.

Valence electrons are all the electrons in an atom except those in the core, or in the filled d- or f- subshells.
A quick way to determine the number of valence electrons for a representative element is to look at which group is it in. 

As you can see in this periodic table, I have drawn on (messily) the group numbers. 

In group 1, there is 1 valence electron for each element. For group 2, there are 2 valence electrons for each element. And so on, until group 8, where there are no valence electrons, because Noble Gases ALWAYS have a stable octet.

The number of valence electrons stays the same as you go up or down a group, but they increase as you go from left to right across the periodic table. 

I'm tired now.

Core Notation

So by this point, we all know how to do electron configuration.

Core Notation is basically just simplifying core notation!

The set of electrons for an atom can be divided into two subsets: core and outer.

The CORE of an atom is the set of electrons with the configuration of the nearest noble gas (He, Ne, Ar, Kr, etc.) that comes before it.

The OUTER electrons consist of all electrons outside the core. These normally take part in chemical reactions.

So, how do you do this "core notation"? 

At first, it made absolutely no sense to me at all.

But as I continued practicing, I found out it's actually pretty simple.

Step 1: Locate the atom and note the noble gas at the end of the row ABOVE the element.

As you can (hopefully) see in this picture of the periodic table, I've highlighted the noble gases that can be used in Core Notation.

For example - Chlorine.

The Electron configuration for Chlorine is 1s² 2s² 2p⁶ 3s² 3p⁵

Okay, so what is the noble gas at the end of the row above the element? Locate Chlorine. You will see that at the end, and up one, is Neon. 

The Electron Configuration for Neon is 1s² 2s² 2p⁶

STEP 2: Replace the part of the configuration corresponding to the configuration of the noble gas, with the SYMBOL for the NOBLE GAS in SQUARE BRACKETS. 

So in this case, the CORE NOTATION of Chlorine would be: 

It's simple! This way, you don't have to keep writing out 1s² 2s² 2p⁶ etc.

More of the Periodic Table!

The 1800s was huge for discoveries regarding the periodic table. Here's what you need to know:

Law of Octaves - John Newland
He proposed that elements are arranged according to their atomic weight

Mendeleev:
Discovered that certain features of elements recurred when elements were arranged in order according to mass. Therefore, he decided to organize the elements in periods and families or groups, also known in the general English language as a row or a column. He even left gaps in the table, leaving room for other elements with similar characteristics to be discovered. (Smart cookie!) He is known as the 'father' of the periodic table.

                                                      The smart cookie! (Mendeleev)
Modern Times:
Periodic Law : Elements recur periodically when arranged from lowest to highest atomic number.
-Elements are arranged according to their atomic number. (Got that wrong on the test, damn! But at least you'll know now!)

Here are some fun videos for you!

The Mendeleev Song!
History on Mendeleev
Newland documentary

Now your daily chemistry related lolcat!

Enjoy and I hope everyone did great on the test!