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Topic: Predicting products of reactions: Ag + CuSO4 -->  (Read 51961 times)

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Offline Bel-p

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Predicting products of reactions: Ag + CuSO4 -->
« on: May 17, 2006, 07:01:01 AM »
OK, it's me again with another question about predicting products of a reaction.  I found a worksheet on the internet (http://misterguch.brinkster.net/001_002.doc) with loads of equation questions, and I started with Section 3, Q1:

Predict the products of the following reaction:
1) Ag +  CuSO4 -->

OK, so the easy answer is to think that there must be a reaction otherwise they wouldn't be asking for the product, so the answer is AgSO4 + Cu, and then balance it:
2Ag + CuSO4 --> Ag2SO4 + Cu

BUT what I don't understand is why there's a reaction at all - Siver is less reactive (lower on the reactivity series) than copper so why does it react with SO4 and displace the copper?  I thought something only displace another element if the displacing element was more reactive than the other one. 

Am I missing something very basic?
« Last Edit: May 20, 2006, 12:49:45 PM by Mitch »

Offline Borek

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Re: Predicting products of reactions
« Reply #1 on: May 17, 2006, 07:05:20 AM »
OK, so the easy answer is to think that there must be a reaction otherwise they wouldn't be asking for the product

And that's where you are wrong :)

There is no reaction.

Please use charges whenever you refer to ions, and please refer to ions whenever you are talking about water solutions :)
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Offline Bel-p

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Re: Predicting products of reactions
« Reply #2 on: May 17, 2006, 07:22:38 AM »
Aha, so I was right to think there shouldn't be a reaction - hurray and what a relief!

In that case it's a bit worrying that it's on a worksheet on the internet with the answer below being AgSO4. That will confuse people (like me!).   I'll write to the owner of the site about it.

Point taken re using charges when referring to ions, I think you mean I should have said SO42- instead of SO4

I'm not sure what you mean when you say:
Quote
please refer to ions whenever you are talking about water solutions
does this relate to my question here?

Thanks Borek.



Offline Borek

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Re: Predicting products of reactions
« Reply #3 on: May 17, 2006, 07:36:44 AM »
Point taken re using charges when referring to ions, I think you mean I should have said SO42- instead of SO4?

Exactly.

Quote
I'm not sure what you mean when you say:
Quote
please refer to ions whenever you are talking about water solutions
does this relate to my question here?

Yes - these reactions take place in water. The real question was in fact whether

Cu2+ + 2Ag -> Cu + 2Ag+

is possible. SO42- is only a spectator.
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Offline Bel-p

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Re: Predicting products of reactions
« Reply #4 on: May 17, 2006, 02:19:27 PM »
Oh no, now I'm really confused.  I thought it was going to be Ag or Cu+ that would react with the SO4+, not Ag and Cu+ reacting together.  I'm not sure I knew that metals could react together...

Offline Borek

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Re: Predicting products of reactions
« Reply #5 on: May 17, 2006, 03:00:23 PM »
In this case displacement is a reaction between metal ion and solid metal - solid becames ions, ions became solid. That's what reactivity series tells us about metals - which one will be ionic, which elemental after the reaction.
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Offline mike

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Re: Predicting products of reactions
« Reply #6 on: May 17, 2006, 09:07:56 PM »
You can still write the reaction equation, this doesn't mean the reaction will actually happen, but you can still write it.
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Offline rctrackstar2007

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Re: Predicting products of reactions
« Reply #7 on: May 18, 2006, 03:14:07 PM »
Oh no, now I'm really confused.  I thought it was going to be Ag or Cu+ that would react with the SO4+, not Ag and Cu+ reacting together.  I'm not sure I knew that metals could react together...

no, no, the two are not reacting together. the SO42- is a spectator ion and does not get included in the reaction. does that make sense?
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Offline Bel-p

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Re: Predicting products of reactions
« Reply #8 on: May 19, 2006, 08:33:57 PM »
no, no, the two are not reacting together. the SO42- is a spectator ion and does not get included in the reaction. does that make sense?
No, not really.

Offline tennis freak

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Re: Predicting products of reactions
« Reply #9 on: May 19, 2006, 09:23:34 PM »
what he is trying to say (i believe) is that the SO42- is not a reacting molecule and thus does not need to be in the net ionic equation which is just for the things that react together, better?
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Offline rctrackstar2007

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Re: Predicting products of reactions
« Reply #10 on: May 20, 2006, 01:58:05 PM »
no, no, the two are not reacting together. the SO42- is a spectator ion and does not get included in the reaction. does that make sense?
No, not really.

the whole reaction is Ag +  CuSO4 --> Cu + Ag2SO4

but being that the SO4 doesn't do anything, only the anions do something, you won't include it in your reaction

the net ionic equation would then be: Ag + Cu2+ --> Cu + Ag-

make sense yet?
AP Chemistry Squad Member [002]

The world is like an atom. The not-quite-as-intelligent people are the nucleus all packed together sharing a common...everything. We, we are the electrons. Granted we're not as smart as these engineers and what-not so we're most likely in the first orbital, but we're the electrons of this giant atom. We all have differing intelligences and ideas and we are separated from the nucleus which makes us better because no one really cares about how a nucleus acts. It's the electrons that make chemistry, except for nuclear chem, of course, which I am a big fan of.

-Your's truly, 2006;
  written to describe the HS chem student apart from the average being

Offline mrdeadman

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Re: Predicting products of reactions
« Reply #11 on: May 20, 2006, 02:01:55 PM »
Oh no, now I'm really confused.  I thought it was going to be Ag or Cu+ that would react with the SO4+, not Ag and Cu+ reacting together.  I'm not sure I knew that metals could react together...
it's an oxidation-reduction reaction. i guess you haven't learned about those yet. one metal gains electrons and one metal loses them. whichever metal is more reactive will lose electrons and will combine with the anion. the anion does not change, which is why it is left out in the overall written reaction.
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Offline mrdeadman

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Re: Predicting products of reactions
« Reply #12 on: May 20, 2006, 02:03:59 PM »
but being that the SO4 doesn't do anything, only the anions do something, you won't include it in your reaction
i think you mean cation
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Offline rctrackstar2007

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Re: Predicting products of reactions
« Reply #13 on: May 20, 2006, 02:06:52 PM »
but being that the SO4 doesn't do anything, only the anions do something, you won't include it in your reaction
i think you mean cation

oops, that is what i meant  :P

Bel-p, have you learned about redox, and do you understand this all yet?
AP Chemistry Squad Member [002]

The world is like an atom. The not-quite-as-intelligent people are the nucleus all packed together sharing a common...everything. We, we are the electrons. Granted we're not as smart as these engineers and what-not so we're most likely in the first orbital, but we're the electrons of this giant atom. We all have differing intelligences and ideas and we are separated from the nucleus which makes us better because no one really cares about how a nucleus acts. It's the electrons that make chemistry, except for nuclear chem, of course, which I am a big fan of.

-Your's truly, 2006;
  written to describe the HS chem student apart from the average being

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