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Everything You Ever Needed To Know About pH

Part I: Quick Review of Basic Chemistry

From Thomas Hynes

Now everything we have discussed up to this point is nothing more than one atom of hydrogen. But Hydrogen does not like to live alone. It has infinity for bonding to other atoms. It likes to really bond to other hydrogen atoms. This in turns is what gives us hydrogen gas. Now because the protons equal the number of electrons with in orbit around this pairing, the molecule of hydrogen gas is considered neutral in its charge. Positive charges balance out the negative charges.

Hydrogen does bond with other atoms such as oxygen, giving us water or chemically speaking H2O. The chemical symbols that are discussed here should be explained. They become important with chemical reactions.

The H we already know stand for the hydrogen atom. The 2 is listed as subscript, and represents the number of hydrogen atoms. The O is our new molecule that we will soon discuss shortly; this is Oxygen.

So we now have two hydrogen atoms bound to an oxygen atom, giving us water. Now other atoms can bond to this new atom due to the unbalanced electrical charges with in the atom itself. We will get there soon enough, but before we do, you need to know a few things.

Atoms are a bit more complicated, and can become quite bizarre at times showing up as an isotope or as an ion. Here are two new words, so what exactly are these two things?

An Isotope is nothing more than the same molecule having different neutrons in the atoms nucleus. Hydrogen, as you can see, we will use this atom a lot in our discussion comes in three other forms: Protium, Deuterium (a proton and a neutron) and Tritium (A proton and two neutrons).

Hydrogen is the only element whose isotopes have been given different names. Deuterium and Tritium are both used as a fuel in nuclear fusion reactors. Interestingly enough, 1 atom of deuterium is found in about every 6,000 ordinary hydrogen atoms.

Hydrogen can also come in an ionic form. This is the part where we take a bigger step towards what pH really is. You see if hydrogen has no electron than it is an ion. It is classified as an ion, because the proton, which is all that’s left, is a positively charged particle.

Now because the hydrogen atom lost its electron, it has now become a positively charged particle. In this case H+. Now it should be noted if there were two + + signs there that would mean that the atom had a +2 charge. But since our lonely hydrogen ion only has one proton, then it only has a charge of +1. Can you see just from this small fact alone, that this atom can now seek out and attach itself to another atom that has a negative charge? If it did then the atom would become electrically stable again.

Okay, this is a good place to kind of relax, take a breath, and re-review some of the ideas expressed here. I want to make sure that before you go any further, that you fully understand what it is that is going on. Look, most people get lost in chemistry; I do not want that to happen to you. There are some really simple ideas here that are easy to understand if you just think about it.

And before we go any further, you need to understand what is going on. Because in our next discussion, we are going to cover some ways that atoms bond to each, and why that is so important in what we as marine aquarists are dealing with.

Some other chemicals that Hydrogen bonds with are Calcium, Oxygen and Carbon. And again because these three atoms above all have their own unique charges, and ability to bond and dissociate with one another, makes it important to what factors give us the water quality that we hobbyists seek to achieve. And why alkalinity and pH are two separate issues.

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Part II: Quick Review of Basic Chemistry
Part III: Quick Review of Basic Chemistry

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