Chemical Forums

Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: organicguy on June 15, 2014, 01:45:31 PM

Title: (Au 3+ or Ti 3+) and both get 2e-, comparing voltage potential?
Post by: organicguy on June 15, 2014, 01:45:31 PM

If Au 3+ and Ti 3+ both get reduced with only 2 e-, how would you compare their voltage potentials?

Without being given any data, how can you compare the voltage potentials of these two?

Au3+ > Ti 3+
or
Ti 3+ > Au 3+ ?

Thanks!

Title: Re: (Au 3+ or Ti 3+) and both get 2e-, comparing voltage potential?
Post by: organicguy on June 17, 2014, 10:56:21 AM

any help :(

Title: Re: (Au 3+ or Ti 3+) and both get 2e-, comparing voltage potential?
Post by: Borek on June 17, 2014, 04:58:52 PM

I can't think of any reliable way - other than measuring.

Title: Re: (Au 3+ or Ti 3+) and both get 2e-, comparing voltage potential?
Post by: Arkcon on June 17, 2014, 07:21:12 PM

So you've only added 2e^- to each?  How did you control that -- adding just two, no more no less?  Or is this purely hypothetical?  And is the Au- ion stable?  I'm sorry no experts have come in to help you, but I can't understand your question.

Title: Re: (Au 3+ or Ti 3+) and both get 2e-, comparing voltage potential?
Post by: organicguy on June 18, 2014, 09:57:47 AM

Quote from: Arkcon on June 17, 2014, 07:21:12 PM

So you've only added 2e^- to each?  How did you control that -- adding just two, no more no less?  Or is this purely hypothetical?  And is the Au- ion stable?  I'm sorry no experts have come in to help you, but I can't understand your question.

Thank you for your response!

So I suppose it would be ok to answer this question in a qualitative manner, rather than a quantitative manner with a discrete voltage or E_cell.

My thoughts on this are:

The Au 3+ has 6 electrons in its d orbital, adding 2 electrons will give it 8. Since the d orbital is most stable at 5 or 10 electrons, neither configurations of Au (3+ vs 1+) is particularly stable.

The Ti 3+ has lost both its electrons in d orbital and 1 electron from the 4s orbital (I think thats how it would loose them), so adding 2 electrons will make it have a filled 4s orbital and 1 electron in the 3d orbital (making it Ti 1+).

I think that the 1 electron in the d orbital of Ti 1+ might be less stable than the configuration of Au 1+ with 8 electrons in the d orbital. So my though is that the voltage potential of Au3+ should be a larger positive than Ti 3+ because it is easier to add 2 electrons? (Au3+ > Ti3+)

Does that sound correct, or am I totally off?