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Rules of Solubility
Dr. A.K. Williams, Ph.D
San Pedro, Costa Rica

This will be a very short page. It could also be a very important page in that it applies to all the other pages on this site.

As is most fields or endeavors there are certain rules that apply. In many cases, I don't like rules. Rules that are imposed for no good reason are, in my opinion, not only worthless, but also despicable. As we used to say in the military, rules are for damn fools and second lieutenants. This referred to useless or counter-productive rules.

There are, however, other kinds of rules. Rules that govern how things work. Man did not make these rules. He just discovered them. They were made and employed by whatever force created the physical world.

I want to provide you with a few simple rules concerning chemicals and how they behave when they are mixed up with water. With these rules you can predict whether or not any inorganic chemical is going to dissolve in the water or whether it is going settle to the bottom and just lie there. If it settles and you want it to dissolve, you must change it's salt form. If your Silver Chloride is lying in the bottom of a flask and you want it to dissolve, these rules will allow you to dissolve it without having to even e-mail me. The rules will tell you that if you simply convert it to a nitrate instead of a chloride, it will dissolve. We all know that all you have to do is add a little nitric acid to make this conversion. The Silver will now dissolve in water.

Ha!!, you say, so that's how ol KEN in cr does it! He just has a few rules that are not generally available to the rest of us. That is absolutely correct! Read on and I will impart to you the secrets of inorganic solubility that were made before the first glob of molten Gold was spewed from a volcano
The beauty of it is that you don't have to memorize the rules. Just print a hard copy; stick it up on the basement wall for quick reference. Might put a copy in your pocket too, so that you can impress less-knowledgeable friends.

O.K., here it comes, deez ah de rules!!

Rules of Solubility

  1. Nitrates, chlorates, and acetates of all metals are water-soluble. No exceptions.
  2. All Sodium, Potassium, and ammonium salts are soluble in water. No exceptions.
  3. Chloride salts of all metals except Lead, Silver, and Mercury 1 (ous) are water-soluble. E.g., Mercurous Iodide is insoluble. Water insoluble Chlorides, Bromides, and Iodides are also insoluble in dilute acids.
  4. Carbonates, Phosphates, Borates, Sulfites, Chromates, and Arsenates of all metals except for sodium, Potassium, and Ammonia are water-soluble.
  5. Sulfides of all metals except for Barium, Calcium, Magnesium, Sodium, Potassium, and Ammonia are water-soluble.
  6. Oxides and Hydroxides are water insoluble except for Sodium, Potassium, and ammonia. (Hydroxides of Calcium and Barium are moderately soluble in water.

Well guys, that’s about it. There is a little more info about how to convert these salts from Chloride to Nitrate, Nitrate to Hydroxide, Hydroxide to Iodide etc. Gonna do that on another page that will be about “mass action”.

All this Stuff is Fun, and Educational Too!!
Where else can you get that?

This document maintained by A.K. Williams. Material Copyright © 1999 A.K. Williams

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