Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: positiveion on January 04, 2010, 08:34:23 AM
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Cu + AgNO3 --> Ag + Cu(NO3)2
Why is it Cu(NO3)2 and not CuNO3?
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What charge does copper normally have in ionic compounds?
What is the charge on the nitrate (NO3) ion?
Clive
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2+ and -
But I only know this because I was 'told' it. I don't know WHY Cu is 2+ and Ag is not.
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For metallic ions charges can be found/determined using periodic table and the electronic configuration of the elements.
In the case of polyatomic ions their charge can be determined using more advanced theories, like MO and/or LCAO. However - at early stages of learning chemistry it is easier just to remember NO3-; at later stages it doesn't make sense to use each time heavyweight approach to things that can be remembered so easily ;)
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Lol but Cu and Ag are in the same group? Why do their charges differ?
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Again, it has to do with more advanced topics.
A simple explination is that nature favors half filled and then filled electron sublevels.
Cu will have a charge of 2+ or 3+, most likely. The transition metals are kind of funky like that.
If I remember correctly, silver has a 1+ because of its size, it only likes to let go of one of its atoms. It becomes more stable in its ion form because of that half filled s sublevel.
Feel free to check me on this, I'm pretty sure that I got part of that explination wrong.
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Again, it has to do with more advanced topics.
A simple explination is that nature favors half filled and then filled electron sublevels.
Cu will have a charge of 2+ or 3+, most likely. The transition metals are kind of funky like that.
If I remember correctly, silver has a 1+ because of its size, it only likes to let go of one of its atoms. It becomes more stable in its ion form because of that half filled s sublevel.
Feel free to check me on this, I'm pretty sure that I got part of that explination wrong.
Cu's common oxidation states are +2 and +1. And +2 is favoured in certain cases because of its high hydration enthalpy. The stability of Cu+ is explained well based on the fully filled d-orbital. Please note that this is the case if the hydration enthalpy is not so high.
Ag's common oxidation state is +1 and it is probably well explained based on a completely filled d-orbital, and not a half-filled s-subshell, because it doesn't have a helf-filled s-subshell.
(Try writing the electronic configuration. It comes in handy many a time )
Probably you were in a hurry...you said 'atoms' instead of 'electrons' :P
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Cu's common oxidation states are +2 and +1. And +2 is favoured in certain cases because of its high hydration enthalpy.
Just another small clarification on this topic as I'm not really into these inorganic topics... do you mean that the hydration enthalpy is negative and bigger in modulus so the dissolution of these ions is more favored?
[O.T. Nice to see you're still working hard in the forum... I've been out for a few months due to school but you didn't lose any time ;D]
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Cu's common oxidation states are +2 and +1. And +2 is favoured in certain cases because of its high hydration enthalpy.
Just another small clarification on this topic as I'm not really into these inorganic topics... do you mean that the hydration enthalpy is negative and bigger in modulus so the dissolution of these ions is more favored?
Yes.
[O.T. Nice to see you're still working hard in the forum... I've been out for a few months due to school but you didn't lose any time ;D]
I simply love this forum...I've learnt a lot, and i'm happy i've been able to help a few people. :)