CHRIS25
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Come on? Silver 1 or 4 or 11 valence....
it depends on who you ask, and I can list the references if you like. This is bloody confusing. I am trying to understand the transition metals to
know exactly how many valence electrons they have (my particular interest right now is Silver because I want to do a reaction); I was trying to do the
ionic equation for Ag + HNO3 listing the oxidation numbers, drawing the lewis dots and even, yes even building the models on my desk with
those children's red white and grey molecule building thingys. I came unstucjk at what I thought was the simplest thing in the universe to work out
when I could not work out the valence electrons in Silver.
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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Texium
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Silver only exists in compounds as 1+ except in very rare cases.
[Edited on 5-10-2014 by zts16]
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blogfast25
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Nitric acid is different from other strong acids in the sense that the nitrate ion in acidic conditions is also an oxidiser:
HNO3(l) + H2O === > H3O+ + NO3(-) (dissociation of nitric acid in water)
The H3O+ is an oxidiser in the way we discussed.
But the nitrate is an oxidiser too, and gets reduced to NO:
NO<sub>3</sub><sup>-</sup> === > NO
Add two H2O on the right, to balance in O:
NO<sub>3</sub><sup>-</sup> === > NO + 2 H<sub>2</sub>O
Add H<sup>+</sup> to the left to balance in H:
NO<sub>3</sub><sup>-</sup> + 4 H<sup>+</sup> === > NO + 2 H<sub>2</sub>O
Now add 3 e to make it neutral:
NO<sub>3</sub><sup>-</sup> + 4 H<sup>+</sup> + 3 e<sup>-</sup> === > NO + 2
H<sub>2</sub>O
In air, the NO immediately reoxidises to NO<sub>2</sub>, hence the brown fumes when you dissolve metals in nitric acid.
Metals like silver and copper cannot be oxidised by H3O+ alone, hence the use of nitric acid. They won't dissolve in H2SO4 or HCl (copper does
dissolve in conc. H2SO4 but that's another story).
+1 is Ag's main oxidation state but it can be pushed to +2 in extreme conditions.
[Edited on 10-5-2014 by blogfast25]
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CHRIS25
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Yes I was originally at 1 valence electron but then I looked here:http://www.ptable.com/#Property/Valence and it clearly states 4. Then that caused
me to research further and I came across this: https://uk.answers.yahoo.com/question/index?qid=200803271358...
Which I ignored for obvious reasons apart from noticing 11 valence, so I searched further and further and I kept seeing 4 and then 1 again.
Then I had a nervous breakdown.
So I will stick with 1 seeing that 1 is actually in its outer shell, why 4 though?
@Blogfast exactly what I was doing just as I read your post, but your explanation just confirms taht at least on this area I am getting things more
right now. It was just this valence thing.
[Edited on 10-5-2014 by CHRIS25]
[Edited on 10-5-2014 by CHRIS25]
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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blogfast25
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Quote: Originally posted by CHRIS25  |
Yes I was originally at 1 valence electron but then I looked here: and it clearly states 4. Then that caused me to research further and I came across
this: https://uk.answers.yahoo.com/question/index?qid=200803271358...
Which I ignored for obvious reasons apart from noticing 11 valence, so I searched further and further and I kept seeing 4 and then 1 again.
Then I had a nervous breakdown.
So I will stick with 1 seeing that 1 is actually in its outer shell, why 4 though? |
[Kr] 4d<sup>10</sup> 5s<sup>1</sup> is the electron configuration of Ag. The 5s<sup>1</sup> is the lone valence
electron.
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CHRIS25
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sorry blogfast now you've lost me, I have not even dared to touch on orbitals yet - could you though confirm for, me since we know that NO is oxidized
immediately on liberation from water but NO2 is Not produced in solution, that the stoichiometrically correct amount in solution should be based on A)
since this is what is produced 'in' solution, i have seen B) tauted about but I disagree (at the moment). I am not being finiglety or pedantic, i am
just trying to exact more precision in my chemistry than I did many months ago.
A) 3 Ag + 4 HNO3 = 3 AgNO3 + 2 H2O + NO
B) Ag + 2 HNO3 = AgNO3 + H2O + NO2
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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BromicAcid
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Valence 4 does not exist as far as I have seen. The main silver compound that had been assigned a formal +4 oxidation state,
AgO<sub>2</sub> was later found via x-ray crystalography and other techniques to actually be a mix of +3 and +1 oxidation states and is
listed correctly on the wiki article as Silver (I,III) Oxide.
You can see +2 in some common compounds like AgF<sub>2</sub>.
[Edited on 5/10/2014 by BromicAcid]
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blogfast25
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Chris:
A) is correct.
The NO then oxidises to NO2 but that is a separate event.
[Edited on 10-5-2014 by blogfast25]
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CHRIS25
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Ok Bromic, but what is confusing me is that if you hover over all the transition metals on this table, the valence electron listed is hardly ever in
agreement with what I am reading 'logically' as the outer shell valence listed. After all it is what is on the outer shell that is valence. If it's
not then I will abandon chemistry and take up embroidery!
[Edited on 10-5-2014 by CHRIS25]
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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blogfast25
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Which table are you referring to? The periodic table or a specific periodic table you found on Tinternets?
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Texium
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Yes, the outermost energy level, 5, has 1 electron, because silver prefers to store the electron that would be in 5s2 in 4d10 so
that the 4th energy level is full. Because of that, it has only 5s1
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CHRIS25
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this one http://www.ptable.com/#Property/Valence
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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blogfast25
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Chris:
That table contains some errors and some over-simplifications: for Fe it gives +6 but that is only the HIGHEST one and the least stable at that.
With the transition elements (D-block elements) often some or all of the d orbital electrons are also 'available'. For instance for Ti we have [Ar]
3d2 4s2, which would suggest valence 2. But the 3d2 electron are energetically speaking sufficiently close to the 4s ones to be able to act as valence
electrons also. So Ti's main oxidation state is +4. This is true of the other elements of that group.
These atoms don't really care about the somewhat simplistic 'rules' we imagine: if it leads to a stable state it will happen, no matter how much of an
aberration it may look like to us.
[Edited on 10-5-2014 by blogfast25]
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CHRIS25
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Ok Blogfast I guess I will have to find a decent table now. I aqm still getting confused over redox. I had to pick a complex one! The silver is
oxidized by the nitrate ion, the hydrogen atom has of course dissociated I understand all this. But where there is Oxidation there must be reduction.
Now when I balance the Nitric acid charge on the left with the nitrate charge from silver nitrate on the right I see no change Except that the
silver has lost one electron and is now more positively charged. If the nitrate has oxidized silver, where is the reducing agent? and what the hell
has been reduced?
[Edited on 10-5-2014 by CHRIS25]
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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CHRIS25
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I missed this post - so I did pick a complicated one - I just threw my plastic silver nitrate model across the room....I still can't see any changes,
I would expect to find something that has Gained electrons and is now more negatively charged - is it hiding?
[Edited on 10-5-2014 by CHRIS25]
Ok it is hiding, no wonder I could not see it, it was in the NO3, so the N in NO3 has absolutely no charge because it is in a polyatomic
configuration; but when liberated as NO it now has a +2 charge - HAVE I GOT IT NOW....please.....
[Edited on 10-5-2014 by CHRIS25]
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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blogfast25
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Chris:
The Ag has lost an electron, so it has been oxidised.
Work out the oxidation numbers for N in the nitrate and in the NO. In nitrate the oxidation number of N is +5. In NO it is +2. There's your reduction:
it's the nitrogen in one of the nitrate ions that has absorbed (very simply put!) the electrons from the silver. Note that three nitrate ions are
spectators: you find them both on the left and on the right, unchanged.
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CHRIS25
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| Quote: Originally posted by blogfast25 | Chris:
The Ag has lost an electron, so it has been oxidised.
Work out the oxidation numbers for N in the nitrate and in the NO. In nitrate the oxidation number of N is +5. In NO it is +2. There's your reduction:
it's the nitrogen in one of the nitrate ions that has absorbed (very simply put!) the electrons from the silver. Note that three nitrate ions are
spectators: you find them both on the left and on the right, unchanged. |
Relief at last - I am getting it - slowly with bumps and bruises. Thankyou Blogfast.
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
|
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Magpie
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Therefore Ag is the reducing agent.
The single most important condition for a successful synthesis is good mixing - Nicodem
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CHRIS25
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Yes, thanks Magpie, now I understand, and nitrate is the Oxidizer, which by its very nature is a powerful oxidizer anyway, but the complexity for me
was suddenly realizing that HNO3 is polyatomic and I overlooked the N after the H had dissociated into the water.
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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macckone
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Recent research on NaCl shows that at extreme pressure,
the valence categorization as we know it breaks down.
http://www.sciencedaily.com/releases/2013/12/131219142313.ht...
Valence rules are rules of general applicability and apply in
most cases. For silver the rule is +1. That doesn't mean that
other valences can't or don't exist. Nor can the compounds
we use at STP be expected to exist in the same form at
extreme pressures. And there is evidence that on a universal
scale compounds exist at either extreme pressure or absolute
vacuum with very little at what we consider STP.
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CHRIS25
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Hi very interesting article, and it reminds about some laws of physics being turned upside down in cryogenic chambers.
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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