Benzene – A Wonder Compound

Benzene: The aromatic circle

This chemical was crafted by extremely inventive chemists in the 19th Century, benzene is a beautifully symmetric molecule with 6 carbons and 6 hydrogens. The carbons in benzene are held together by an ‘aromatic’ bond. The word aromatic was coined by those early chemists to describe the smells emitted by these molecules. However, in chemistry the word quickly shifted to define the chemical properties of this special bond.

Why is there a circle  drawn in the middle  of benzene  structure????

I just decided on taking on the challenge of explaining this in an ultra simplified way, with minimal chemistry vocabulary.

Imagine you were a time travelling caveman and you had a very primitive vocabulary. Well, on your trip to the future let’s say you encounter a mule. You’ve never seen anything like it before. You have no word to describe a mule, but you do have words for horse and donkey. So you might call this creature a horse-donkey. Maybe you decide to write it out like this:

[ Horse ←→ Donkey ]

To show that it is kind of a horse and kind of a donkey. (What you are NOT trying to say is that it changes back and forth from a horse to a donkey).

This is a lot like what we have to do in Chemistry. The models we have and the structures we draw are basically a primitive language we are using to describe something a bit more complex. Our primitive “chemistry languages” tend to describe things as being very black and white, where they are either one thing or the other.

However in real life these things often exist in shades of grey. One of those shades of grey is Resonance. It’s a circumstance where the model didn’t quite fit and now we have to draw several things on paper and say “this one thing is a combination of these other things”.

So this is the resonance structure for benzene:

As you can see, the double bonds are on opposite sides in the two depictions. If we were draw benzene like this:

Well… That’s a bit like saying the mule is a donkey, which it is not. This drawing is not *exactly* correct (though everyone will know this is depicting benzene and it is an accepted way to draw it). The glaring problem with it is that in real life, it doesn’t alternate between double and single bonds. Every bond “looks” the same. So we draw this:

It’s better but it’s still not totally accurate. This makes it look like there are double bonds all the way around, when in fact the bonds that exist are something in between double and single bonds.

How about this?

That’s probably the best one yet, but nobody wants to draw all those dashes all the time. So in the end laziness wins:

(One ring to rule them all)

Draw enough of these darn things and you will surely come to embrace the ring whenever you can.

Applications of Benzene in Daily Life

Uses of benzene in everyday life give positive and negative impact for us, start for food industry, healthy industry and medicine, plastic industry, rubber and also military necessary. Besides that effect of benzene, it also has bad effect if we did not careful about it.

  • Toluene (Methyl Benzene)

In daily life, we ever paint wall, door or paint big building. Have you ever smelled it paint ? Well, it is smell of toluene as chemicals compounds that we always use for paint material. Other name of toluene is methyl benzene as part organic chemical compounds.

  • Phenol (Hydroxy Benzene / Phenyl Alcohol)

It has many function in daily life such as disinfectant wood preservative, colour substance synthetic, medicine, plastic material and also coagulating protein, phenol also can be dangerous if it attached to our skin. The effect if phenol attached to our skin are skin will get damage of it, scald, and shows redness behind. 

  • Benzoic Acid (Carboxylatebenzane)

Benzoic acid is chemicals compounds has many used for food preservative. Beside for that function it also works for raw material for phenol manufacture.

  • Trinitro Benzene (TNB)

Explosives material can be found on trinitro benzene (TNB). Mostly uses of high explosive TNB are for mining and military activity. Other uses is for measure small pH, agents for vulcanizing natural rubber and also other explosives of synthesis intermediates.

Experts recommended to avoid direct contact with TNB which is believed to cause healthy problem if it contained to water. The most frequently of high concentrate TNB caused anemia (blood decrease to bring oxygen to the whole body). This will give effect to our skin turn to blue or purple color. We need to avoid dust, smoke from burning materials or reaction effect of TNB because it has other side such as headache, nausea. Wearing gloves, glasses, jackets are recommended when we received stuffs with TNB materials inside. 

  • Nitro Benzene

Do you realize where is good smell of deodorizer on soap we use everyday come from? Yes, it was nitro benzene inside it. Beside it function for deodorizer, it also used as basic materials for making aniline (organic compound in making aromatics).  


Sr. Secondary School

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