nyll
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NaOH vs KOH
Hi everyone. I've been wondering about this for quite some time and I have searched the web without finding a definite answer.
The matter is that on many hydrolysis and isomerization procedures using strong bases, some authors use KOH, while others seem to prefer NaOH.
I just want to know if that is just a matter of preference/availability or if it does actually matter for pratical purposes, since they both are quite
similar compounds.
KOH is more expensive and not very OTC where I live also, so it would be good if someone more experienced could clear this out. I'm sure many people
here would also like to know. 
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nezza
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They are both similar in strength. The choice of which to use depends on circumstances. KOH is much more soluble in alcohol than NaOH and in aqueous
solutions the carbonate does not precipitate out like Na2CO3.
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Nicodem
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Quote: Originally posted by nyll  | | I just want to know if that is just a matter of preference/availability or if it does actually matter for pratical purposes, since they both are quite
similar compounds. |
Of course it matters for some practical purposes, but not all. It mostly depends on the solvent used and the functions the KOH or NaOH are supposed to
have. For example, in water it is mostly irrelevant in most cases if the KOH/NaOH is used solely as a base. However, in solvents that are less able in
solvating cations, the difference in basicity and other properties of KOH and NaOH can be huge. Most of these differences originate from the acidity
difference between the sodium vs. potassium cation. Na<sup>+</sup> is considerably more acidic and harder than K<sup>+</sup>
and thus the NaOH is consequently considerably less basic in most solvents. The difference is even more obvious when comparison is made also with LiOH
and CsOH. Read upon the HSAB theory to understand the basics in regard to how hardness/softness affects solvation, coordination and proton affinity.
| Quote: | | I've been wondering about this for quite some time and I have searched the web without finding a definite answer. |
You should improve your searching skills. This topic has been already disused on the forum.
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