Oxidationszahlen CuSO⁴?
Hey
Wie kann ich davon die Oxidationszahlen bestimmen?
Und das besteht ja aus Cu2+ und SO⁴2-, aber woher weiß ich das? Also klar, Metalle können nur Kationen bilden, aber warum gibt Cu genau 2 Elektronen ab? Hat es nicht drei Außenelektronen, die es loswerden will? Wie bestimme ich das bei Nebengruppen?
The oxidation number of copper cannot be predicted well; Although +II is the highest, +I and +III are also present. However, it is necessary to know this because there is no rule on this (generally oxidation numbers in the secondary groups are problematic, but Cu, Ag and Au are particularly hairy).
Fortunately, you can easily derive the correct oxidation figures here. You know that the Ion SO42 is twice negatively charged, so the electroneutrality of the whole Cu2+ must be present: vat(II) sulfate. In the sulfate ion itself, you can say that the oxygen will have the oxidation number −II (as is very often) so sulfur must be present as S+VI so that we can have a total of two negative oxygens for SO4.2 come.
(But there is also a very air-sensitive Cu2SO4).
And how do I know SO4 must be negative exactly two times?
You know that by learning the names and charges from the most common types of ions one by one (for school purposes, the maximum is 50; those that really occur are no more than 25…).
Or you know reference connections from which you can derive the charge. In the case of the sulfate anion, sulfuric acid is suitable (H2SO4). If you then consider that acid molecules according to an acid definition bound hydrogen in the form of protons (H+), it becomes clear that the sulfate anion must be twice negatively charged when the sulfuric acid splits off its two protons and thus the sulfate acid residue emerges.
Either way, you don’t get around learning…
If you had any idea of atomic construction, the periodic system of the elements, of bonds (and Lewis formulas), then you could definitely also unlock the charge of the vast majority of ions. But if you had the idea, you probably wouldn’t need it anymore because you would certainly have so much experience in chemistry that you wouldn’t ask because of, for example, the charge of the sulfate anion, because you would also know that.
As I said, you’ll have to learn. How vocabulary of a language…
LG from the Waterkant