Wednesday, January 7, 2009

Chemistry... Preparing Salt....

There are two types of salts, soluble and non-soluble. There are two ways to prepare soluble salts, I think. That's what I learned in chemistry class today. Why in the world do we need to learn about how to make this kind of salts? Will we ever use it, high unlikely unless we get into a field related to it, like chemical engineering?

Well, the first method to form soluble salts is by mixing an acid and an alkali through a process called titration. The product of this process is dilute salt solution. Then, we let it evaporate until we get a saturated salt solution. After getting the solution, we cool it or let it undergo a process called crystallization to turn the solution into crystal form. The salts created from this process will contain either sodium, potassium or ammonium ions.

Another method is by reacting acid with metallic oxides, metals or carbonates. The reaction produces salt solution and excess solid. It is then filtered to separate the salt solution and the solid. Once it's filtered, we let it dry or cool it to get dry salt crystals. Any salts with impurities can be purified by the process called recrystallization.

Insoluble salts on the other hand, are made by a totally different method, that is through double decomposition, by using the precipitation method. I don't understand what it means by double decomposition... Someone explain to me? Haha...

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