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Tuesday, May 24, 2011

It's Just Organic Chemistry!

There is a course requirement,
That bends the brightest minds.
The mention of its very name,
Sends shivers up young spines!  

You might have guessed which course I mean,
It starts with"o" and ends with "ee",
Try not to get too panicky,
It's just organic chemistry!

If you want to learn this well, and easy,
I recommend Baltimore's CCBC,
Dr. DiCara explains things as simple as pie,
(And begins every class with her award winning smile.)

Now here's a rhyme to help you out,
So cast aside your fears and doubts.
 I guarantee by time it's   done,
You’ll say “Hey! Chemistry is really of fun!"

So here we go one piece at a time,
Please, try to be serious,
(Did I just see you smile?)

And so. Without further delay
Let's begin giving compounds  
Their  IUPAC names:

The first thing to know about compound names,
Is they’re based on how many carbons
Are In the longest chain.

Ethyl ,methyl, proplyl, butyl,
Learning Greek is never futile.
Pentyl, hexyl heptyl, octyl, non,


Once your carbon count is done

The next step requires  counting bonds.

If all the bonds are single,
Then the compound’s an alkane.
Double bonds make alkenes;
And alkine is  the triple bond name.

To put these all together now,
Let's name a three carbon chain,
In Greek the three are  propyl;
Singly bonded, it's propane.
propane puppy scultpture

(With double bonds we'd say its propene,
Triples are propine,
Let's take it for a spin with an eight carbon chain, 
Octane, Octene, Octyne.

Now here’s where things start getting fun,
As we progress in this instructional;
Let's talk about a carbon chain,
Aldehyde vs. Ketone
With  a parent group that's functional:

Aldehydes and keytones
are a general classification,
That shows how doubly bonded O's
Can change a compounds designation

( depending on the carbonyl carbon's location,
and the double bond's origin and it's destination.) 

Like, if the terminal carbon ( on a given chain)
Has a double bonded oxygen, coming off it's side,
And that carbonyl  C has a hydrogen, too, 
Then the group's called  "aldehyde."

And you know how we name  aldehydes, 
They sound like Pall, Vall and Hall,  
So, let's  name a three carbon group with an aldehyde ending,
You guessed! It's   "propanall."


And an aldehyde that ends with  "H"
Is called an acetal,
Hemi means there's an O-H group,
Without H or O-H it's "ketal."

Alcohol reacting with Ketone to form Hemiketal and Ketal 

What's a ketal, after all?
It's the group that's derived from ketones,
Ketones have three carbon, all lined up,
And on the carbonyll's  a double bonded O.

Well, all  this compound naming
Makes you stop, sometimes and  blink,
'Cause  everything you thought was simple,
Isn't as you think!

Well,  if your  brain is somewhat  straining,
And you'd love to have a drink,
You can  fix something real zingy ,
Fizzy, bubbly, spiked, and pink.

Like, say you want to have a drink
That's made with alcohol,
Put O-H on a two carbon chain
And Voila! It's methanol.

R-O-H Alcohol + a Methyl group= Methyl Alcohol or Methanol

But if you add an  O-H substituant
To  a benzene ring,
You've synthesized phenol. 
(That's the common name we give to  "bezyl alcohol)
Phenol Showing Electrostatic Potential

Now, alcohol seeks company
In this lonesome big organic world;
If it partners with a double bond O, for drinks,  
She gets the reputation of  a  carboxylic-acid  girl.

Carboxylic Acid

(But don't forget, it's a two step deal,
Making carboxyls is not so placid;   
First  C-O-H gets oxidized to doubly bond aldehydes, 
Then alde hydrate (hemi-acetals) are oxidized to acid. 

Oxidation of Alcohol ( R-O-H) to Aldehyde ( C=O-H) To Acid (C-O-O-H)

(And all this, just for a bit of

Yet, when it comes to things all sour, carboxylic acids rule the day! 
By oxidizing primary alcohols,

C-O-H becomes a doubly bonded acid, hurray.

Now, acids can be oh, so  generous,  
Despite their bad rep. and sour taste, 
They catalyze reaction times,
And  donate protons to form conjugate base.

A Bronsted Acid is a Proton Donor


An Arrehnius Acid Dissociates to Form Conjugate Bases and Acids 

Lea's Cherry Pie

And here is something quite amazing,
 That you might not have guessed, from the start;
An acid can  transform into something  quite romantic,
Or juicy fruity, or delicious or tart.

You see, if you love the smell of jasmine, yumm,
Banana flavored cherry pie, or rum,
It's cool to know you can synthesize these, 
Or ....the flavor  of  bubble gum! 

Esterfication of a Primary Alcohol

All you need to do is mix 
An acid that's carbolic,
With the right primary alcohol, whichever you wish,
And poof, you've made an Ester, go ahead and whiff. 

( 'Cause If you mix carboxylic acid,
With a primary alcohol,
You'll get yourself a new functional group,
Named "Ester", R-C-O-O-R.) 

Dehydration rection of a primary alcohol with one mole of carboxylic acid

Naming Esters is simple and fun,
You just need to know who's the dad and who's  the son;

The acid is the parent, as you know
But  COOH loses one bond (uh oh)
that's replaced quickly with the  R-group of an alcohol ,and so,
You're left with  an "R-carboxyl-oate" (and one mole of H2O.)


Now, if all this talk of compounds,
(What they  lose and what they gain,)
Has you clutching your poor forehead
And you feel yourself grow faint,

Just relax we've got you covered,
Smell this oil of  wintergreen,
Called methyl salycilate;  
Ester of methyl alcohol plus salicylic acid is precisely what you need.

Well, esters are such very cool things,
They' smell like flowers or  fruit, or wintergreen,
Saponified carboxylic salt mycels  leaves you squeaky ester clean,
And an amide's what you get... when you substitute an amine.

Dehydration reaction of a carboxy;ic acide with an amine

Now what's an amine? You might not NO2
'Amine? I don't even kow'ya!',
But this little rascal is your friend from way back when,
If you've ever scrubb-a-dubbed with  ammonia.



You see, basically, ammonia is
The opposite of a proton donor,
It's a Nitrogen atom, with three H's bonded,
(And  it also has a 'loner')

This is why it's shape is  trigonal pyramidal,
And why it can be ionized a whole lot, or a little.

Ionization of an amine forms ammonia

And I know you already know this,
And would never hesitate,
To say that protons in a high dipole state,
Dipole Moment
Are always eager to escape. 

And while we're on the topic
Of proton giving  and taking,
Let's talk about Bronstead- Lowry 
And the strengths of acids and bases.

An acid is strong when it wants to give it up
To anyone who asks, it's easy,
Remembering  these strong acid names
Makes  conjugation equations breezy:

Hydrochloric, Hydrobromic, 
Nitric, Sufuric, Iodic,
Circle them on your periodic chart,
There isn't  much more to it!

Spicy salsa? Five alarm chilly?
What, exactly did you think?
Helapeno` peppers with  beer and burritos, 
You ate it all but the kitchen sink!

So, If last night you partied hard, 
And now your stomach is asking "WHY?",
Before you  eat another thing,    
Take a swig of antacid Alkline Hydroxide 

Sodium, Potassium,
Cesium and Calcium,
Strong bases take all that  acids have to give,
While buffers can run back and forth,  maintaining  pH equilibrium.

And should  you ever need to calculate
The concentration of two compounds
When they hit their  equilibrium state,
Go ahead, you can do it. ( And this doesn't depend upon rate:)

The equillibrium constant, known as K(eq),
Is something you can calculate, it's not so hard to do;
To know the concentration  between reactants and what they make, 
Just think about what determines when you give and when you take:

So, to find the concentrations 
That reflect the balanced state, 
You can talk to old  Fritz Haber,
( Don't you wish he were your neighbor?)

He said, to find the point  of equillibrium ,
"Tween reactants and  what they make,
Equate  the concentration of your product
To  reactant molarity (times K.)
Equilibrium constant=  molar concentration of product over  reactants

Just  remember to raise  the coeficients
Into  concentration exponents,
And when  you report your  answer,
Count  those sig figs with great dilligence!,

And if you do all this, and keep calm and stay resillient,
I promise you my, orgo friend,
your acuracy  will be.....brilliant! "

( Under a high ionic,
constant temperature and pressure
experiemental environment.)

And if you need to know
How fast this happens ( and how slow,)
Divide the change in concentration by how much time has passed,
(For first order reactions,) then plot and calculate the slope.

So now you know the way to show
How much gets made of what,
And how quickly all this happens.
But how can you know the  equillibrium point,
When dealing with bases and acids?

Well,  Hendersohn and Hasselbeck, 
Two  guys who were quite classic,
Defined the  acid/base equillibrium constant: 
As pH plus (the log of) conjugate base over acid.

But enough is enough,
These equations overload my brain!
Instead, let's move onto isomers;
Identical molecular formulas, with different names.

There are three types of isomers 
Structural, geometric and chiral
You know that they are  isomer's if their formula's are the same
But you'd have to break a bond or two for them to have the same name.

Structural isomers have different bond relationships,
Geometric's are cis and trans,
Chiral molecules are never superimposable,
( Just like your left and right hands.)

Geometric isomerism    Structural Isomerism;        Chiral isomerism

And if you ever need to know,
The number of isomers possible,
What exactly should you do?

I'll answer:  just count the chiral carbons at  the crossroads, in a row,
Then use that number as you exponent,
Raised up to the base of two.

The number that you find will be,
The value of  isomeric possibility.

Well, now that you have had a taste
Of what this course is like,
I hope you fell a bit reassured,
(It's like learning  to ride a bike.)

At first it's pretty wobbly,
So many things can go wrong.
But after a while you find yourself riding
So smoothly, while singing this song:

"There is a course requirement,
That bends the brightest minds
The mention of it's very name
Sends shivers up young spines..."

But this time when you sing it,
You will catch yourself with a smile,
Cause now you know, it's not that bad,
If you take it just one carbon at a time!



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