Book Extract #8: Oil and Water Chemistry #1

I remember the first time I saw kerosene and water mixed together.  We used to have an old kerosene heater and I was curious to see what would happen if you mixed the kerosene and water together.  Since the kerosene was a nice sky blue colour, I wondered whether it would make the water blue.

Much to my surprise, the kerosene and water separated into two discrete layers, with the kerosene on top.  I was fascinated by this – I’d never seen this before.  Two liquids were mixed together, but not mixing at all.

This phenomenon explains an awful lot of what we see in the world around us, particularly in the kitchen and laundry, so let’s look at – why don’t oil and water mix?

To understand this, we have to go right back to the beginning.  And we’ll work our way slowly forward from there.

The most basic things on earth are elements – everything in existence is composed of one or more of these. These can be represented in a table:

Now, here’s the funny bit. In terms of all the things that we see in the world around us, we can essentially divide everything into two categories.

If you look at the table above, in the second row you will see that element number 6 has the chemical symbol “C” – which of course refers to Carbon.

Carbon has a unique property – the ability to link to itself in long chains or rings of infinite length and with an infinite number of structures and shapes. Think of it as chemical Lego – you buy a box of Lego bricks and you can fashion them into any shape you want. So it is with carbon.

For this reason, carbon-based molecules have their own category – organic.

Organic chemistry is also the chemistry of life (hence the term “organic”). We are organic, as we are carbon-based life forms. Inorganic chemistry is everything else.

In other words, the two major branches of chemistry are organic and inorganic. Organic chemistry concerns itself with the chemistry of one element only – carbon, and inorganic chemistry concerns itself with the chemistry of the other 109 elements in the table above.