Gen Chem reviw book chap 1

jftoscano2011
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Gen Chem reviw book chap 1

Postby jftoscano2011 » Fri Jul 27, 2018 6:28 pm

Hello there,

I am a little confused about question #7 of the passage questions at the end of chapter 1 of the chemistry and organic chemistry review book. The explanation on the book is not clear to me. I was wondering if anyone can help me clarify why niobium's 5s subshell will be filled after loss of 3 electrons and in a half-filled state after loss of 4 electrons.

Thanks,

Juan
NS_Tutor_Phil
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Re: Gen Chem reviw book chap 1

Postby NS_Tutor_Phil » Sun Jul 29, 2018 7:57 pm

Hey Juan,
Nb's base electron configuration is [Kr] 5s2 3d3 . Thus losing 3 electrons leaves you at [Kr] 5s2.
jftoscano2011
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Re: Gen Chem reviw book chap 1

Postby jftoscano2011 » Mon Jul 30, 2018 3:33 pm

Hello @NS_Tutor_Phil,

you mean the base electron configuration is 5s^2 4d^3?
I though that when you take away electron from the electron configuration you start from the highest n level, in this case 5s. so the configuration would be 4d^2 right?

Best,

Juan
NS_Tutor_Katelyn
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Re: Gen Chem reviw book chap 1

Postby NS_Tutor_Katelyn » Mon Jul 30, 2018 6:11 pm

jftoscano2011 wrote:Hello @NS_Tutor_Phil,

you mean the base electron configuration is 5s^2 4d^3?
I though that when you take away electron from the electron configuration you start from the highest n level, in this case 5s. so the configuration would be 4d^2 right?

Best,

Juan


You're correct, the configuration is 5s2, 4d3, and transition metals typically lose electrons from their s subshell before their d subshell. The reason C is the correct answer is because Nb can lose 4 electrons without reaching a complete octet in its valence shell, which explains why the difference between each ionization level in the table is approximately equivalent. Let me know if that makes sense!

-Kate
Katelyn Sawyer
Senior Tutor
katelyn@nextsteptestprep.com
NS_Tutor_Phil
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Re: Gen Chem reviw book chap 1

Postby NS_Tutor_Phil » Tue Jul 31, 2018 12:20 am

Yep, sorry about that. I need to make sure I have a fresh cup of coffee before I start typing! You are correct about pulling off the valence electrons first in the traditional organization. However, many times atoms will immediately reorganize though, shifting their electrons from the inner d orbital to the outer valence s orbital (which stabilizes to a lower energy organization). As Katelyn was saying, the small changes shown in the first several electron losses seem to imply that they are including this reorganization in the electron losses.
MCATnNYC
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Re: Gen Chem reviw book chap 1

Postby MCATnNYC » Wed Aug 08, 2018 2:18 am

Hi Phil and Kate,
Would the ground state of Nb be [Kr]5s2, 4d3 or [Kr]5s1, 4d4? A pal and I are now confused because of this:

http://www.chemistry.pomona.edu/chemist ... iobium.htm

-Lin
NS_Tutor_Katelyn
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Re: Gen Chem reviw book chap 1

Postby NS_Tutor_Katelyn » Wed Aug 08, 2018 5:12 pm

MCATnNYC wrote:Hi Phil and Kate,
Would the ground state of Nb be [Kr]5s2, 4d3 or [Kr]5s1, 4d4? A pal and I are now confused because of this:

http://www.chemistry.pomona.edu/chemist ... iobium.htm

-Lin


As far as I know it would be 5s2 4d3. If it is 5s1 4d4 it would be due to some elemental unique exception that would be unlikely to matter for the MCAT.
Katelyn Sawyer
Senior Tutor
katelyn@nextsteptestprep.com

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