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Everything You Ever Needed To Know About pH

Part III: Quick Review of Basic Chemistry - Page 2

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Okay lets get back to discussing what a mole is. A mole is nothing more than 6.02 x 1023 of atoms. That’s it. That is all you need to know. Well it’s a bit more complicated than that, but sufficed to say, that’s all I am willing to get into. Not good enough for you? Okay, if you take equal samples of each element, than that sample will have 6.02 x 1023 atoms in it. But you must remember that since each element has a different weight to it, that the amount of say Gold (Au), will be smaller than say Hydrogen (H).

So getting back to pH. If you have pure water, of any given sample, that sample will have a pH of 7. Now this magical number is right in the middle of the pH scale, therefore we can say that the pH of the sample of water we are working with is neutral. The water is neither acidic nor base.

So taking what we know about the pH scale we know that the mathematical formula is written as such 1.0 x 10-7 for a sample of water with a neutral pH. Okay that is nice and everything but what does it mean? It means this. In Pure water a small percentage of the molecules are dissociated into H+ and OH- ions, and because the concentrations of these two elements are equal, this pH is said to be neutral.

In our other sample of water with a pH reading of 4, that sample contains more H+ than OH- ions. By the way I forgot to mention what that OH- ion is, it has a name, it’s a Hydroxyl Ion, all it really is, is a H2O molecule that lost a molecule of hydrogen. You have heard the term free radical; well this is an example of one!

So now you know what pH is, and how it is measured, and why it can be changed. Oh wait, take a step back, we didn’t discuss this yet did we. Well we will, but for now we are going to let this be a shorter chapter. So go back, and review if you need to the concepts discussed here in the third chapter.

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

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