And last but not least...

Dear dedicated followers of our cat-filled magnificently informative blog, we, the Beryllium Chemists, would like to give a big THANK YOU for increasing our page views  having an interest in our blog! THIS WILL BE THE LAST POST OF THE SCHOOL YEAR, so you won't hear from us for a long long time. We hope that each post enhanced your level of understanding and helped you cram study for upcoming tests (cough cough) ;) 
Without further ado... our last post about organic chemistry (YES) will be on ALICYLICS AND AROMATICS!!


Alicyclics And Aromatics

•  Cyclic Hydrocarbons (allicyclics): a ring shaped structure formed by hydrocarbons
• use the prefix "cyclo" in the name
• The general formula is CnH2n
• Obviously, there must be 3 or more carbons to form the ring structure
• When numbering the cyclic hydrocarbons, you may start anywhere and move at anydirection of the ring
• Numbering can be clockwise or counterclockwise for the main chain only!
• They may have branches as well, and be branches
• more reactive than the simpe straight chains

 
Rules For Naming Branched Cycloalkanes
 

Now recall your elementary geometry math skills! These are the shapes that alicyclics can form, with each edge of the shape as a hydrocarbon. The number of hydrocarbons (edges) would correspond to the alkane names (propane, butane, hexane.. etc)

1. Count the number of edges (carbons)
2. If there is 1 side group, no numbering is needed
3. If there is more than 1 carbon then the first side group is placed at the number 1 position of the ring (How to choose which is first: lowest numbering, alphabetically)
4. Cyclic substituent is just named like the simple straight chain side group
5. Prefix is "cyclo" and is placed before the main chain name
 
Cycloalkanes, Cycloalkenes, Cycloalkynes
 
- Cycloalkenes = double bonds
- Cycloalkynes = triple bonds
- Carbon number 1 and 2 are akways the double or triple bonds
 
Examples:
 
cyclobutene                               cyclooctyne






1-ethyl-3-methylcyclohexane

Notice how we don't start at methyl to produce 3-ethyl-1-methylcyclohexane. Remember that if there are side groups that are equally apart (tied), then start with the alphabetically lower one!
 
Branched Alicyclics

Basically, alicycylics as side chains have the same rules as any other side groups. The only exception is that there is a "cyclo-" prefix.


In this example, it is called 3-cyclobutylpropene










Aromatics
 
- Most of the time have a pleasant odour
- Has at least 1 benezene ring (C6H6) with 3 double bonds in between the carbons
 

- Can be represented with a circle in the middle
- Can be either parent or side chain

- Electrons can share equally and are able to change positions, this is called delocalization
- They are very stable because of delocalization
- Not as reactive as cycloalkenes and cycloalkynes
 
Aromatic Naming
- "benzene" is the parent chain name
- If it's a side chain, the prefix is "phenyl-"
 
<--- Ex. 2-chloro-1-iodo-3-methylbenzene




Ex.

2-phenylhexane
 










Well, it has been a great year serving you guys! So long, and farewell. :)
GOODLUCK STUDYING FOR TESTS AND FINALS and have a great summer!

Carboxylic Acids, Esters, Ethers, Amines

Are you still surviving? Is organic chemistry making your blood boil? 

NO FEAR. BERYLLIUM CHEMISTS ARE HERE!

Last post, we talked about some of the basic functional groups that you may come across. Today, we will teach you some more complex functional groups! (Yay or nay?) Don't understand the basics yet? Refer to the posts below!

Carboxylic Acids

R - functional group with one valence electron

• Acidic; can be neutralized with a base
• Compounds that contains the carboxyl functional group -COOH (a double bonded O and an OH) at the end of the chain
• Methanoic acid is the simplest acid
• Start counting from the side with the carboxyl functional group

NAMING: At the end of the main chain name, drop the "e" and add "-oic acid"

Example: Acetic acid (Ethanoic acid)

How to draw it? First start off with your basic -COOH structure. We know that ethane means two carbons, so just attach another carbon to the structure. (Remember the octet rule for bonding - three hydrogens would be bonded to the carbon!)

Another example: Name this acid

1. The longest chain of carbon is 3. The ending of the name would be 'propanoic acid'.
2. Counting from the carboxyl functional group, we find that there are two methyl's at the location "2" and one bromo at "3".
3. Putting it in alphabetical order, the name of this acid would be: 3-bromo-2,2-dimethylpropanoic acid.

Esters

• formed by combining a carboxylic acid with an alcohol functional group
• Oxygen separates the 'alcyl' and 'alkyl' group
• can be easily converted back into its original states
• has a fruit odour 

NAMING: When naming, the alkyl group is named first and has an '-yl' ending. When naming the acyl group (carboxylic acid), remove the '-oic acid' and replace it with '-oate'

Example: 

1. Count the alkyl chain first. The longest chain consists of 5 carbons, so it is named 'pentyl'.
2. Now looking at the acyl group, the longest chain has four carbons - 'butanoate'.
3. Put it all together and you have: pentyl butanoate!

Ethers (EE-THERS)

• The main difference between ethers and esters is that there is no double-bonded oxygen
• Ethers are side groups: Oxygen starts the side group and is connected to two alkyl chains
• has a pleasant odour, highly flammable, colorless, insoluble in water, and acts as good solvents

NAMING: Ether + Alkane

Same procedure as before, except the endings for ethers are '-oxy'.

Example: 

Can you try to guess what the name of this ether is? If you guessed 1,1-dimethoxyethane, good job! There are two ether side groups containing methyl located at the first carbon, and the longest chain is two.

Give this one a try: 2-methoxy-2,2-dimethylethane

(The answer will be at the bottom of this post)

We are almost through... Bear with me!

Amines!

• functional group that has Nitrogen bonded to 3 Hydrogens or Carbons
• it is a side group
• related to ammonia (NH3)
• has a "fishy" odour
• soluble
• They're organic bases that can easily form salts when reacted with acids (through neutralization of course!)

NAMING: Side group + "amino" + parent chain

Standard naming rules, but the alkyls attached to the Nitrogen is followed by "amino". (Eg. methylamino)

Example: 2-aminopentane

Here is the solution to 2-methoxy-2,2-dimethylethane!

Whew, too much chemistry for one night. Off to bed!

Functional Groups

How is this not the funniest joke you've ever heard?!?!

So. This enlightening blog post discusses functional groups.  If you're like me, and just drew a blank on what that is... well. How very unfortunate.

Anyways... Here we're gonna discuss 5 of the functional groups, which are organic compounds containing more than just C and H. Getting more fo your monnaayyy.  But technically we're only talking about 4... because halide and nitro compounds apparently count as the same group. huh. 

Halides
Fluoro (F)
Chloro (Cl)
Bromo (Br)
Iodo (I) [i know iodo sounds like dodo... but its really not...]

Nitro
Nitro (NO2)

Not that hard, right? Good 'cause you have to memorise those prefixes!

So these halides and nitro compound thingies can attach to alkanes/enes/ynes.  and you add a number (di, tri, tetra, etc) in front of the functional group if more than one of them portrudes off the carbon chain.

For example...

3-bromo-butane looks like...

Well this is awkward... I cant figure out how to rotate it LOL

whatever 2,3-diiodopentene looks like...

and TADA. not bad, right?




Fun fact of the day: Did you know alcohol is poisonous? hmm.

Alcohols are the next functional group, which is generally easy to identify.  Why, you ask? Well, my furry friend, because all alcohols contain a hydroxide!! (OH, for you chemistry failures.  And no not OOHHH I get it I mean OH - the chemical formula for hydroxide)

So when naming alcohols, you look at the longest chain, and then add OL to the ending. 
That is... Ethane with an OH attached would become ethanOL.

here is a pretty picture of of ethanOL

Note: If there is no number in front of the alcohol, then we assume that the hydroxide is attached to carbon #1

Say you have 2 OHs attached you your ethane.  So you'd need a DI (chemistry..get it DIE CHEMISTRY) somewhere in there.  But obviously chemists are too meanyfacey to put it in the logical spot, so instead our ethane with 2 OHs would become ethaneDIOL. duh. but not.


The last couple functional groups are very similar, so make sure you know which is which.

Aldehydes:
-have a double bonded oxygen attached to the beginning/end of the chain
-end with AL (do not confuse the ending with that of an alcohol!)

Ketones
-have a double bonded oxygen attached to one of the carbons in the middle of the chain
-end with NONE (eg pentaNONE, propaNONE)

EXAMPLE:

Now... Wheeeeeerreee is the double bonded oxygen....

Well waddya know?! It looks like it's at the end of the chain!! and since we start from the side with the double bonded oxygen on it... ^that chain would be named propanAL.

WEEEEEEEEEEEEE

MORE ORGANIC CHEMISTRY: AlkENEs and AlkYNEs

Last post we learned about Alkanes, which were hydrocarbons that were interconnected by single bonds. Today, we will talk about Alkenes and Alkynes, which are hydrocarbons that have double bonds and triple bonds, respectively.

ALKENES
Alkenes are unsaturated hydrocarbons, meaning they form double or triple bonds. For alkenes, the double bond(s) can be located anywhere. HOWEVER, you always start counting the parent chain from the side that is CLOSEST to whichever double bond. In other words, the double bond always has the lowest number and is placed in front of the parent chain name.

Now here are some rules for Naming Alkenes:

• General formula: CnH2n
• Start from the element closest to the double bond.
• The standard naming rules for organic chem apply here.
• Replace the ending from "-ane" to "-ene".
• If there is more than one double bond, use the same greek prefixes before the "-ene" (eg. butadiene)

Here is an example: 2,3-dimethyl-2-pentene

Now a little something extra for Alkenes is that there is something called "cis & trans."
What is that you may ask? WELL LET ME TELL YOU FIRST. WHY YOU GOTTA ASK SO MANY QUESTIONS. SHEEESH.YOU IMPATIENT PERSON. (just kidding)
They are geometric isomers, which has the same formula but different geometry. There are different isomers, so that is why we give them different names like 'cis' and 'trans' based on their geometry.

Now from the image below, we can decide if a compound would be cis or trans.

• If the larger groups are both above (A,B) or below (D,E) the plane of the bond is  "cis". 
• If the larger groups are across the plane of the bond (A,E) or (B,D) then it is "trans".
• If there are 2 identical groups on either end of the double bond (A,D) or (B,E) then there are no geometric isomers => there are no need for cis or trans.
• Cis and trans are placed at the very beginning of the name

Get it? Got it? Okay! Moving on the alkynes (yay..)



but wait, let's do some exercises!
WOOHOO practice questions!
1) Draw 4-methyl-1,2-pentadiene
2) Draw trans-2-hexene
3) Name









Answers:
1)
2)






3) 3,4-diethylhexene

ALKYNES
Alkynes are also unsaturated hydrocarbons, forming triple bonds. The same rules of alkenes apply for alkynes.

Now here are some rules for Naming Alkynes:

• General formula: CnH2n-2
• Start from the element closest to the triple bond.
• The standard naming rules for organic chem apply here.
• Replace the ending from "-ane" to "-yne".

Here is an example: 2,3-dimethyl-2-pentyne

See? It's not that hard. All that's different is that there is a triple bond rather than a double bond!
Now lets test those smarticle skills of yours... Here are some practice questions:

1) Draw 4-ethyl-4-methyl-2-heptyne.
2) Draw 3,3,5-trimethyloctyne
3) Name

Answers:
1)







2)







3) 3-heptyne


And there you have it!
Enjoy organic chemistry .... evil smile*

Organic Chemistry: The Chemistry of Carbon

It's chemistry.... BUT ORGANIC! Hahahaha just kidding.

 

 
Organic compounds are chemical compounds which contain carbon (C). Recall that carbides, carbonates, and some oxides of carbon are NOT organic - inorganic.
 
Properties of Organic Compounds
 
- It has the ablility to link with other atoms. There are 3 different kinds of bonds; 
single bonds, 

double bonds,

and triple bonds, 

 
- When they form chains of carbon, the atoms can be linked in different patterns, such as a straight line, circular parttern or a    branched parrtern.
- They have a low melting point and are weak and non-electrolytes.
- The versatility of the orginial compunds make it very a important branch of chemistry.
 
Alkanes
 
- They are unbranched and have a straight chain.
- They only consist of hydrogen and carbon.
- They are saturated hydrocarbons which means that they all have carbon atoms bonded by single bonds.
- They are capable with mixing in water; they are non-polar molecules.
- Their structure/geometry; tetrahedron   
 
Naming
 
When naming Alkanes, you've got to change the ending to "anes". MEMORIZE THESE!
 
Names of Alkanes                     Molecular Formula
 
Methane                                    CH4                                 
Ethane                                      C2H6
Propane                                    C3H8
Butane                                      C4H10
Pentane                                    C5H12
Hexane                                     C6H14
Heptane                                    C7H16
Octane                                      C8H18
Nonane                                     C9H20
Decane                                     C10H22


People always have trouble memorizing the first four, so here is a mnenomic to help:
Maggie Enjoys Peanut Butter :)

Gerneral formula is CnH2n+2
 
Branched Hydrocarbons
 
- They can have side carbons which is also hydrocarbon chains.
- They can be called substituted hydrocarbons or just branched hydrocarbons.
- In the Alkyl group, an alkane lost one H atom, so when naming alkyl groups,  the ending changes to "yl".
 
Ex: 
Methane --> Methyl 
 methylpentane
 
the methyl part = alkyl group
the pentane part = parent hydrocarbon or longest chain
 
Naming
 
When there are more than just one type of alkyl group, you must list them alphabetically. So if there is ethyl and methyl, ethyl would come first. 


*Also, when you have a side group or branched hydrocarbons, always start counting from the side that is NEAREST to the branch!
 
What do you mean by 'counting' ?
Well, young grasshopper, in the future you will come across names of organic compounds that have numbers in them. These numbers indicate the location of the side groups to clarify where each are (because some chains have TONS of side groups and it's hard to keep track!)
HOW TO NAME AN ALKANE (STEPS):

1. Count and find the longest chain of carbons. 
2. Refer to the chart above to obtain the name of the alkane depending of the number of carbons.
3. If there are any side groups, start counting from the side NEAREST to it!
4. Write the number of the location of any side groups shown. If there are more than one of the same side group in the same location, use commas to separate them. (eg. 2,2 or 3,3,3)
5. List the side groups alphabetically.
6. Use a dash (-) to separate the number and the name of the side group.
7. The name of the parent chain is always last!

Let's try this:


 


Now, take a look at the green and red numbers. Each shows an option of where to start counting. Which side is closest to the first side group?


If you answered the right side, BINGO! The red colored numbers are correct, and the green numbers are incorrect.


Now let's name it!

1. Pentane = longest chain
2. Ethyl (2 hydrocarbons), methyl (1 hydrocarbon) = alkyl groups
3. Position of alkyl group = 3-ethyl, 2-methyl 

3-ethyl-2-methylpentane 

Feel that you know alkanes well enough? Challenge yourself and take this quiz!

Alrightyy, that's all the fundamentals that you need to know! Goodluck!

hubba hubba ;)

VSEPR Theory

What is it?
Valence
Shell
Electron
Pair
Repulsion


This theory allows us to understand and thus be able to predict the structures (or shapes) of molecules in three dimensions. We know that like charges repel, so electron pairs are located as far apart from each other as possible around the central atom. The geometry of a molecule will be the ideal structure that will best prevent the repulsion that are acted upon the electrons.


If there were two bonded electron pairs around an atom, they would situate themselves in exactly 180º. This shape would be called LINEAR.

Domain - region of space that occupies the electron pair

Here is a chart that can help you predict the geometries and angles for molecules based on the NUMBER of BONDED ELECTRON PAIRS

However, when there are lone pairs, the geometry of a compound would be different as shown above because they exert a larger repulsive force. 
So when compounds like NH3 would be expected to have a trigonal planar shape, the hydrogen atoms would actually have the shape of a tetrahedral because there are four electron pairs.

Notice that the repulsive force exerted by the lone pair causes the hydrogen atoms to move closer to one another. This creates a smaller bond angle between the atoms. This is because lone pairs takes up more space than bonded pairs. We can say that the more lone pairs there are, the smaller the bond angle will be.

Here is a chart that includes lone pair structuring that may help:

Also keep in mind that double and triple bonds may also act the same way as lone pairs, reducing the bond angle as well. This is because the domain of the multiple bond takes up more space, thus pushing the other atoms away.

Enjoy!