That’s a possibility. But I got the list not by looking at NaOH solutions. If you look closer, you will see both Lye (KOH) and Lye (NaOH) with no mention of solutions…it is these two catagories that I developed the above list.
I still think I see more cases where KOH is more damaging than NaOH on other websites, but the fact that NaOH is sometimes listed as more damaging is…interesting. So the question could easily become “why are they different at all?”
It would make some sense if the two materials were in different states (solid vs aqueous), but it isn’t terribly obvious from the website.
I’m more likely to believe that there is a misunderstanding on the part of Cole-Parmer (and others?) than there is a fundamental difference in their reactivity. However, I don’t mind at all being shown that I’m wrong, seriously.
I can see how easy it is for them NOT to do the tests themselves, but to gather it from different sources (who may have gotten it somewhere else) and after being put through this filtering the two bases wind up with different reactivities to some materials.
OR…they really DO have different reactivities to some substances…
I’d call Cole Parmer, to get to the bottom of this, but its the weekend and I will be away from my desk all next week, so it will be a while before I can ask them about how they collected the list.
I can not remember why, chemistry classes in the 60’s. But
The same is true of acids. When cleaning a heat exchanger you have to determine which metal is is made of. Copper, stainless steel, steel, irom, brass then which acid to use, murratic, nitric, and others. Use the wrong one and by by heat exchanger.
In the case of potassium ion and sodium ion, the outermost electron has certainly been lost, hydrated or not. The loss of the outermost valence electron is what distinguishes the ionic form from the elemental form.
And I’d rather hydrate NaOH and KOH instead of elemental sodium and potassium any day. (I did a pretty spectacular demonstration once with elemental potassium in water.)
I didn’t say they were identical, just similar. Besides, I was commenting more on spingears’s assertion that any differences in reactivity were obvious “from a visit to the Periodic Table of the Elements.”
It’s merely a solubility issue. Alkaline salts tend to be more soluble in most solvents as you go down the period. That’s why organic chemists so often use Cs[sub]2[/sub]CO[sub]3[/sub], because it will (sort of) go into things like THF, whereas K[sub]2[/sub]CO[sub]3[/sub] is a brick.
OK 20 y chemist here. And there are some terrible answers here (though not all)!
For dilute NaOH and KOH there will be little difference as the Na and K ions will be largely solvated and “spectator”.
For very concentrated solutions (e.g. 80%) there may well be a difference as the ions are less well solvated, and more likely to participate in any reaction, probably as weak Lewis acids. Also the polarity, dielectric contant and amount of ion pairing (and hence “activity” of the ions) will be quite different for concentrated KOH versus NaOH solutions.
Note that the Cole palmer site given lists three strengths of NaOH (20%, 50%, 80%) but only one unstated strength of KOH so it is hard to compare the four. However, even with the NaOH series, the reactivity can vary a lot according to the Cole-P site