Are the oxidation states the same as the charges on common ions? e.g. Is every Group 1 ion +1?

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Posted Sun 20th May, 2012 @ 15:00 by Jack Andrew Riley

4 Answers

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These are the rules for oxidation numbers.

The oxidation of a simple ion is numerically equivilent to the charge on the ion

The sum of all oxidation numbers of all the atoms in a particle must be numerically equal to the total charge.

Group 1 are always has a +1 (so you are right in your question)

Group 2 are always has a +2

Hydrogen is always +1

Oxygen is always -2 unless in peroxides when it is -1

Fluorine is always -1

The oxidation number of an uncombined element is 0

Hope this helps!

Answered Sun 20th May, 2012 @ 20:30 by Sophie
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In simple ions, the oxidation number is the charge on the ion (so an Mg2+ ion will have an oxidation state of +2) - so you're right.

But you have to remember that group 1 metals, group 2 metals and aluminium from group 3 have fixed oxidation states in all of their compounds - +1 for group 1, +2 for group 2 and +3 for aluminium (although that does mean that the charge on their ions is equal to their oxidation state).

Answered Sun 20th May, 2012 @ 15:19 by Mark Gavartin
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I understand oxidation states, I was just wondering if there was a simple way of learning the common ions?

Answered Mon 21st May, 2012 @ 16:15 by Jack Andrew Riley
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The ions want to reach the same electron configuration as the nearest noble gas as this is the most stable. They all want 8 electrons in their outer shell.

Group 1 have to lose an electon to become 1+ and Group 2 have to lose 2 electrons to become 2+. Group 7 have to gain an electron to become 1- and Group 6 have to gain 2 electrons to become 2-. Now they all have 8 in the outer shell.

As for things like NO3- and OH-, you just have to learn them.

Hope this makes sense!

Answered Mon 21st May, 2012 @ 18:57 by Sophie