Acids, Bases, Salts: Can An Oxide Be A Salt?

Chemistry, Education
[caption id="attachment_15469" align="alignright" width="440"] Aluminum chloride, hexahydrate. - Image Victor Claessen CC-SA 3.0.[/caption] Acids, bases, salts: Can an oxide be a salt? Let’s find out. Combine an acid and a base and you often get back a salt and water. This should be no surprise. It is high school chemistry. Assume we have a most simple acid, H-A. Too, we have a most simple base, B-OH. If we react the two, we expect the reaction mechanism to be written, H-A + B-OH → B-A + H2O H2O is, of course, water. B-A is the expected salt. Is An Oxide a Salt? Let us consider an example that deviates from the above simple concept—aluminum. Metals tend toward cationic (+) behavior. Non-metals act in opposite fashion, tending toward anionic (-) behavior. Aluminum…
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Anhydrides – Inorganic and Organic

Anhydrides are compounds that are similar to other compounds from which one or more molecules of water has been eliminated. An anhydride must not be confused with an anhydrous compound. In an anhydrous compound, the water reactant from which it is formed includes water that is attached lightly by weak bonds. Water is not an inherent part of the molecule's structure. Consider cupric sulfate pentahydrate, CuSO₄•5H₂O. This is a blue, crystalline substance. It is a composite structure of one molecule of cupric sulfate and five weakly held molecules of water of crystallization. Those water molecules can be removed quite easily. Powdering the crystals and warming them in a drying oven produces CuSO₄. This anhydrous compound is nearly white. No, it is not an anhydride. Aluminum Oxide Aluminum oxide, Al₂O₃, is an…
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