[peterschmidt3943]

Hello,

I would like to know why in K2O + H20, K20 is the Base and why the product of them is KOH..

My idea is that K, which wants to give his one electrone in his outer shell, shoud "give" his electrones to H20.. isnt it?

[sjb]

Hello,

I would like to know why in K₂O + H₂O, K₂O is the Base and why the product of them is KOH..

My idea is that K, which wants to give his one electron in his outer shell, should "give" his electrons to H₂O. isn't it?

Formally true, however, what is the nature of the potassium-oxygen bond in both reactant and product?

[Enthalpy]

[...] My idea is that K, which wants to give his one electron in its outer shell [...]

No atom separates spontaneously from an electron. This takes 419kJ/mol (4.3eV) even for K. It is a lot: for instance the combustion to H₂O releases 286kJ/mol. Quite the opposite: K can bind with one more electron to make K^- and release 48kJ/mol.

So in the situations where K "loses" an electron, an other atom or molecule must attract this electron even more strongly than K⁺ does. And even that does not happen easily: the + and - ions are never isolated. Either they stick to an other in a solid, or both stick to polar solvent molecules like water which, by proper polarisation and orientation, bring an opposite charge close to the ion. This makes the picture of "ion" far less clear than losing or gaining an electron.

And chemical reactions are almost never between lone atoms. Because lone atoms are so reactive (with exceptions like rare gases), they are already combined in molecules. Chemical reactions only reorganize the atoms from one set of molecules to an other set. Even when writing just "K" (which isn't the case here...) it usually means "solid potassium", which is a molecule with metallic bonds. It takes 89kJ/mol to make lone atoms from it.