So Long, Farewell

Hello! Here's PinchOfKCN!!! ((wave
Why are you so surprised to see me again? Well, I know what you think. You must have though I've left forever, aren't you?
But the truth is, I'm ALWAYS here you see; I creeps around like a spy from the Mole King. And further more, this is my blog, so I can come back anytime I want.

However, I'm not going to teach you any chemistry today, nor to throw a huge review package to help you study for the final.
I'm here to give you a reminder that you mustn't stress too much over the exam, DON'T PANIC.

And don't be like Squidward.

Well I'm afraid now's the time for us to say good-bye to each other. And we might not be able to see each other again. Now I'll bid you good night, and of course, good luck on your chemistry exam :)

~ Pinch Of KCN

No Recess in High School

Helllo ya' all. I feel like we're contradicting ourselves lately. Wait, why is my nose growing???? When we say that was our last blog post of the year, it wasn't. When we say that was going to be our last joke of the year, we didn't mean so. Hopefully these deceiving words of ours didn't hesitate you too much from continuing reading our blog, our very last blog post. Anyways, bear with me for one last time, I got a little treat for you all, an internet (not cookie) treat of course, like usual. [ DON'T SCROLL DOWN JUST YET, I WARN YOU]

So today, our last day together, we'll be looking over the topics called 'Alcyclics and Aromatics.'

Alcyclics, also know as cyclic hydrocarbons is hydrocarbon chain which connect in a circle formation. The prefix "CYCLO-" is used for naming molecules in such formation. The general formula for alcyclics is CNH2N. Yes, it's simple as that!

Let's show it in a example:



Say in diagram #1, top right, there's 3 carbons, which means it's a propane. And since it's an alcyclics, it's then cyclo + propane, which makes it cyclopropane. Na da, easy piesy right?!

As for alkenes and alkynes, simply make the first and second carbon be where the double and/or triple bond situate(s). Therefore, there's no need to indicate the "1" in front of the molecule then for indication purposes.

For branched cycloaka/e/ynes molecules, naming is just the same as we have done before. Let's recap with a slightly newer example:

<--- 1) As for naming, first count the number for the longest carbon chain. In this case it's 6, which means it's a hexane as there's no double nor there's a triple bond.

2) Then you see, it's a cyclic, now add the cyclo- onto it. Now it makes a cyclohexane.

3) Now you look again, you notice there's a CH3 sticking out from one of he carbon. You should treat it the same as we always do. CH3 is also methane. As a side chain, add prefix "methyl-" to cyclohexane, which makes methylcyclohexane. DONE!

Moving on, we got Aromatics. From the word itself, you can smell the aroma already. LOL. Aromatic molecule is a molecule that contains one or more benzene rings. Benzene is C6H6, which holds a structure like the following,



Benzene has the potential to become a parent chain or a side chain. For a side chain, the prefix "phenyl-" is added. For a parent chain, the word "-benzene" is attached as a suffix.

Example time again:

 propyl- + -benzene =  propylbenzene


                         2-phenyl +butane = 2-phenylbutane



You may ask: What's up with that circle stuff in the benzene ring, that shows that electrons can move around the ring. Nothing big. To understand it easier, we suggest you to ignore the meaning of it as it will not affect your naming, aka your grades. Jokes!

Since we're saying goodbye to all of our wonderful blog supporters, we are willing to reveal our identities... just slightly...because we all know the World Wide Web is never too trustworthy. Anyways, if you haven't noticed  already, our  blog is not written by a single person, in fact, it's done by a committee of writers. There are four of us. Just yesterday, a Disney animated cartoon called Recess struck me and I realized wow those four characters do have some parallels with us.

Here is C.L., best represented by Gus Griswald. He is a magnificent storyteller. One of his greatest creation must be the Mole King. And needless to say, he is a super nerdy guy:) Let me show you a head-shot of  him:

    



**Maybe a bit taller than Gus...**

And then, we gotta mention our talented computer geek K.L., she's so good at anything involving computer that I bound to call her my computer master. Her greatest achievement definitely has to be her epic Mole King Game. She is best depicted by Gretchen Grundler. Without further ado, let's find out what she looks like,

    

**Minus the chipmunk teeth and those lovely 'Wizard of Oz' pigtails...looks just right :)**

Oh dear, here we come, our "most dedicated"...ahem...NOT AT ALL...member of our blog committee. That would be our best description of him. His name is Mikey C. Like in the animated TV show, he best resembles Mikey Blumberg. Our nickname for him is Big Mikey because he loves to eat Big Mac...get it?! LOL.


 Mikey before Chem class:                         Mikey during/after Chem class:  

  --------->          




***Definitely much shorter and....fine, I'll  nice for once...a bit slimer...***

And then, there's me, A.L. I love to elaborate on others but definitely not myself. If anyone wishes to do so, go right ahead before Monday. But, here's me, the least interesting one, best portrayed by Ashley Spinelli.
 Something a little less grumpy 

** Take away the toque, the red dress, the striped tights, the boots...we have nothing alike.. sigh**

Alrighty, it seems like you guys all know us now. And this horrifying year-long nightmare is  finally coming to an end. LOL. We miss you... not. Yup we're leaving now, goodbye. Before that, we wish you luck in the upcoming two chemistry tests with the aid of our blog. IF you really love us, leave us a comment below, but don't expect us to get back to you so soon because we're really busy people. I mean it. Okay, さよなら!(sayonara, it means goodbye)!

P.S. here is our group photo, taken some years ago with our then-classmates, can you spot the four of us???


School is going to be out soon, you can soon toss away all your chemistry notes...


{Disclaimer (ONLY ONLY to our blog writers): the last section, aka the writers' biography section is all been done by a computer virus that has overwritten all the jokes I was intended to post. If anything offends you, I sincerely apologize for that. I've tried to remove them but it just doesn't seem to follow my command. Alright, I guess we'll just have to leave this alone in a corner of the internet.}

Carboxylic Acids

Last Joke of the Year---------------------------------------------->












Carboxylic Acids

• They are Organic Acids with a Carboxylic group attached to it. 
• General formula:  R-COOH
• Can be neutralized by a base(like most acids)
• For more information please call: 1-800-PRESS-THE-LINK
• http://www.neok12.com/php/watch.php?v=zX775f6e000247531b025041&t=Organic-Chemistry 

Esters

• Combination of Carboxylic Acids with an Alcohol 
• It has a fruity smell (ie, pineapple, pear, strawberry etc)
• General Form: (figure 2)
• Example ------------------------------------------------------>
• To name an Ester, just drop the "oic" to "oate"
• You can see it has the general form from the Carboxylic Acid from the first diagram
• For the more visual learners, just watch the video below!

Ethers

• An organic compound that contains an oxygen group that is attached to two alkyl(carbon) chains
• General Form:  R–O–R
• Characteristics: very flammable, insoluble in water 
• Naming? Just add "oxy" to the side group.
• Watch the video to learn more! Oh yeah, tons of videos this blog.

Amines

• Contains nitrogen compounds bonded to either Hydrogen and Carbons 
• Characteristics: has fishy smell, soluble in water, easily makes salt when reacted with an acid
• It is related to Ammonia (NH3)
• Naming? Add "amine" to the group that is attached to the Nitrogen atom.

Thanks you for reading this horrifying blog. Enjoy~
Below are some extra videos for review, no need to watch if you understand!

Organic Chemistry, YOU SHALL NOT PASS!

Hola mis amigos! Welcome back to PinchOfKCN's chemistry lessons! Today we're going to continue with the topic "Organic Chemistry", but only more complicated than the last two lessons. Also, I believe this may be one of the LAST blog posts we're gonna have; and I can't wait to wave goodbye to all of you — ——JUST KIDDING.

Anyways, here we are again, talking about organic chemistry functional groups; so what exactly are they?
Functional groups are organic compounds that involves chemical reactions of the molecules. They have different atoms more than just plain old carbon and hydrogen; and these atoms tend to attach to the carbon chain.
There are a lot of functional groups, but today, we're only going to look at "Halides/Nitro compounds", "Alcohols" and "Aldehydes/Keytones".

Halides and Nitro Compounds
In the Alkyl Halides, one of the halogen elements are attached to the carbon chain, and where they will replace one of the hydrogen attached to a carbon.
Consider the follow halide and name it:

Before we start, I should safely assume that you must know each turning point contains one carbon, right? Here's an expended view of the diagram:

However, for time consuming reason, I'll not be drawing out each carbon in the next few examples. 

How to name Halides:

1. First, go find the longest carbon chain

As you all know, the longest carbon chain is the blue one, which is 10. And where there is only single bond in this example, we can quickly assume that we're dealing with a decane.
2. Identify all the branches

Nice and color-coded; when we name halides, we have to change the ending of the halogens from -ine to -o (eg. Fluorine to Fluoro).
3. Write the name according to alphabetical order
Well, just in case you don't know the alphabets, here's a picture for you. And now, we write: 2-chloro-8-ethyl-5-iodo-8-methyl dectane
Same as nitros, the procedure is the same, you just have to replace the halogens with nitrogen.



Alcohols
Alcohols are functional groups that contain a hydroxyl molecule in the hydrocarbon chain, they are, however, very different from the alcohol people drink.
Consider the following diagram and name it:

How to name Alcohols:
1. First, find the longest carbon chain (as always)

In this case, it's ultra easy because there's only one possible obvious chain, which is 6. Right away, we know that this is a hexane.
2. Find the position of the OH branch
Now, count from the side that is closest to the OH branch. In this case, you'll get the number 3.
3. Name the compound
With alcohols, we change the ending of the carbon chain group from -e to -ol, and then add the position of the OH branch in front of it. For this diagram, we write: 3-hexanol
Pretty easy, huh? Well I'm sure there are a lot of hard ones involving alcohols, but considering for demonstration purpose, I will just stick with the easy ones for now :)


Aldehydes
Aldehydes are compounds with a double bonded oxygen at the end of the carbon chain, common examples are methanal, ethanal, and propanal.
Now, try to name the following compound:

1. Find the longest carbon chain (yes, again)

Just a reminder that the last branch is a hydrogen, so you don't count it as one carbon in the chain. As a result, we've got 5 (penta).
2. Identify any branches

Now we have one methyl branch in the second carbon molecule, so we name it as 2-methyl.
3. Name the whole compound
For aldehydes, we change the ending of the carbon group from -e to -al. In this case, our compound would be 2-methyl pentanal.


Ketones
Every time when I saw the word "ketone", I'd always mixed it up with "keystone". They're just....so similar. Anyways, ketones are hydrocarbon chains with a double bonded oxygen molecule, but at the end of the chain.
Consider the following diagram:

1. Find the longest carbon chain (Yes, we all know)
And since we've done this plenty of times, I don't think we need a diagram for the longest carbon chain, because you must be able to tell me that it is 7.
2. Next, find where is the double bonded oxygen located
Usually, we have to count from the nearest end in order to get the number of carbons. But since we have equal number of carbons at both sides of the chain, we can count from either end to achieve an answer of 4 carbons.
3. Name the compound
Lastly, we change the ending of the carbonyl group from -e to -one, and our final answer would be 4-heptanone, also known as the dipropyl keytone——if you would like to use the traditional naming method and impress the teachers.


Now, congratulations for getting over the FIRST PART of organic chemistry functional group! We're going to talk about the second part next time.
So how do you fell right now? I'd say let's give yourself a little pat on the back, and prepare yourself for the next lesson. That's my best advice.
By the way, if you have to choose one from the following photo, which one would be your choice?

If you choose video games, well.....here's what chemistry teachers (and I) have to say before the final exam:

That's it for today's lesson, good day.

Akenes and Alkynes

Our titles just got lamer. We're currently trying to beat our own PinchofKCN-based The Gunness Book of  Records©" feat. "the lamest title for our blog."
<----Awww, begging to learn already. Ok we heard you! So Alkanes, Alkenes, Alkynes....and many more... what is the difference between them anyways? Chemists fiddling around with rhyming schemes? I think not. If you're jumping ahead without reading our previous blog post, I can assure you, you're not saving any time, but instead, you're wasting time. You won't get a heck out of this without the previous knowledge. Or else, you will just end up like me, hours ago... Yup, I am just one of you, not much different from our sincere blog visitors. I was just joking! I am much smarter than that. Way smarter... Without further ado, let's get into it. (To show you all my intelligence. And needless to say, I learn all this in...2 minutes.)

So Alkenes are just some "flavoured" Alkanese. Oops, that was just some side-effects from having too much Pringles! Maybe something more scientific this time. Alkenes are organic compounds containing a double bond between carbons. Similarly, alkynes are organic compounds containing a triple bond between carbons.

The naming for akenes and alkynes, it's very similar to that of alkanes. You can recap that from our older post. The only difference is before you name/number all the branches, you name/number the double bond or triple bond first and place the naming in front of the parent name.

Yes, I can hear your desperate echo! Maybe, my wording isn't clear enough, let's try an example.



That is 2-butene. As simple as that!

Now, let's take a look at how the "real" geometric composition of these alkenes and alkynes.
For 2-pentene, there are two different geometric isomers available. (See below)



* This is only occur when double bonding is present.
CIS isomer: the two branches are on the SAME side of the double bond.
TRANS isomer: the two groups are on DIFFERENT side of the double bond.

                                           ~THE END~



Is this what you're thinking right now? Well, good night and sweet dreams to our fellow readers:)

Do you like organisms? How about chemistry?

Well that was our lamest title ever. Anyways, as you may have guessed, this post's topic is on Organic Chemistry. What is organic chemistry you may ask? Why it's the branch of chemistry that deals with substances containing a common element called Carbon. Carbon is everywhere. It's in the air, in your clothes, your food, medicine, furniture and so on. In fact, nearly one fifth of the human body is carbon.

The special thing about Carbon bonds is that they go more that one way. Sometimes it's straight, while other times it gets together with other carbons to link into a circle. It will even creates branches from a main line of carbons. See below for examples.

 

Straight

Circular

Branched

Hydrocarbons

Today we'll be focusing on a specific group of organic compounds, hydrocarbons. And even more specifically, we will be discussing alkanes and alkyls. Let's start off with alkanes.

Alkanes are a straight, single-bonded chain of carbons with hydrogens.

They are saturated (atoms can't bond to the alkane)

They end in "-ane"

Get it? Well you shouldn't, because we just told you some meaningless definitions and properties. Let's try something a little less abstract. 

This is Propane. As you can see, three carbon atoms are connected in a straight line with Hydrogens filling in the octets. Why is it called propane? IT JUST IS DEAL WITH IT. You'll want to memorize the prefixes for these alkanes. Not too hard. 

The alkanes are a homologous series. They follow a general pattern, in this case, it's C_nH_2n+2. And if you're wondering about what C₁₁H₂₄ is, it's Undecane. "Un" as in 1, and "dec" as in 10. Know your greek prefixes, kids!





Let's move on the alkyls. As you should already know, Carbon can bond with carbon. This gets interesting when hydrocarbons branch off from an alkane, like 2,2-dimethylhexane to the left there. How do we name these complex-looking substances? Well keep readings.

Find the longest chain of carbons. These aren't always in a horizontal line! They can make turns. The important part is finding the longest chain of carbons and the corresponding alkane. In the image to the left, it's a hexane. Cool, we figured out half of the name.

Second, start counting at one end of the chain, and find where it branches off with another carbon. You'll want to count from the end that gives a smaller number to the carbon where it branches off. Again, in the above image, this is the second carbon, so we know the numerical prefixes, 2. Now, what kind of alkyl branches off from there? It's actually very similar to alkanes, except the -ane is replaced with -yl. CH₃ is methyl, C₂H₅ is ethyl and so on. The general form for alkyls is C_nH_2n+1.

Third, find how many of that alkyl there is and add on a prefix. In this case, 2, so dimethyl.

And for this, we're finished with 2,2-dimethylhexane.

Of course, there are more complex substances like multiple branches and different alkyls, but this post is getting long already. You can probably figure it out yourself. Though here's an incomplete example. 2 methyls branch from carbon 3, and one ethyl from carbon 4 on heptane. It'll be 3-ethyl-2,2-dimethylheptane. Alphabetization and all that. If you don't understand all this text stuff, here's a video you lazy student.



Good luck with the test on the 24^th!

I'm too sexy for this blog

Hello there! And welcome, to Pinch of KCN the Blog! Well thank you for visiting us again, currently we've finally reach 3,000 page views, which is kind of unbelievable.
Anyways, back to today's topic, the VSEPR Theory. To be honest, I think it is one the of weirdest theory with the weirdest diagrams and the weirdest name in chemistry history. Nevertheless, we are here to help you further understand this concept, and I must warn you that it requires decent skills on drawing Lewis Dot Diagrams, especially with covalent bonds. If you're still unsure, we highly recommend you to read our previous blog before leanring the VSEPR Theory.

Feeling confident?

Feeling CONFIDENT? Then let's start!

When you first saw the name of this theory, you must be wondering what "VSEPR" stands for, well, it's original name was "Valence Shell Electron Pair Repulsion Theory". Long name, huh? That's why lazy chemists have shortened its name in VSEPR.

What is the VSEPR Theory?
Valence shell electron pair repulsion (VSEPR) rules are a model in chemistry used to predict the shape of individual molecules based upon the extent of electron-pair electrostatic repulsion. The premise of VSEPR is that the valence electron pairs surrounding an atom mutually repel each other, and will therefore adopt an arrangement that minimizes this repulsion, thus determining the molecular geometry. [ctrl+v directly from Wikipedia,the not-so-trusty website]
In our own (and simpler) words, it means that the VSEPR helps to create a geometric model which shows the approximated position of the electrons of all covalent bond molecules. And where like electrons repel each other, their positions tend to be separated from each other as far as possible.
In general, there are about 5-6 simple steps to draw the VSEPR model, of course, if you have your own secret way of doing it, we highly recommend you to use that technique.

Modelling VSEPR with single atomic centered compounds
Single atomic centered compounds are molecules which they have a distinct element surrounded by another series of one-of-a-kind elements. (Eg. CH4, CCl4, and NH3) Now, let's use methane as the example for demonstration.
First, determine the total number of valence electrons of the compound. (Please don't tell me you don't know how to count valence electrons!!（╬￣皿￣）)
C = 4
H4 = 1 x 4= 4
Total number of valence electrons = 4 + 4 = 8
Secondly, draw the Lewis diagram for this compound, which is....

OR

I personally prefer the left one because it gets frustrated when you have drew dots in your chemistry test diagram and your teacher has decided that you did not. 

Thirdly, divide the total number of valence electrons by "2" to get the total coordination number.

CH4 total coordination number = 8/2 = 4

Fourthly, determine the geometric pattern which the compound will be in. The 5 different patterns are shown below:

2 Balloons =linear geometry
3 Balloons =trigonal planar geometry
4 Balloons =tetrahedral geometry
5 Balloons = trigonal bipyramidal geometry
6 Balloons = octahedral geometry
Now, imagine each balloon as one coordination number ; for methane, it has 4 coordination number , so it'll have a tetrahedral geometry shape.
Fifthly, draw the diagram with your artistic skills

Notice that there is a bond angle of 109.47, because like elements tend to repel each other. Well, you might want to ask, how do we know the bonding angle of these compounds, we can't just use a protractor to measure it, can't we?
No worries, here's a useful chat for you.

The AXE system

In the AXE system, you'll see weird formulas with letters like AXmEn. These formulas give you a hint of what the compound should shape like.

A = Central atom
m = The number of molecules or ions surrounding the central metal ion X (also called "ligands")
n = Number of non-bond lone pairs
E = Unbonded electron pairs on the central atom

For example, CH4 will be AX4.

So that's all for today's lesson! Feel stressed out?
Well, I'm not surprise if you said yes—everyone feels tired after reading long passages.
So here's an easy rubric cube for you, now solve it in 1 second.

Challenge denied.