Question on Ionization Energy!

[treeclimbingmonkey]

Can someone please explain this? I am really confused.

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[FrameshiftAndrew]

There are two lenses through which you can tackle this: gen chem knowledge and test-taking skills.

From a gen chem standpoint, the idea behind Hund's rule is that an electron is more stable when it has a whole orbital to itself than when it shares an orbital with an electron of opposite spin.

From a test-taking perspective, even if you've never heard of (or have totally forgotten) Hund's rule, this question is essentially saying "something weird happens between N and O, what would happen if that wasn't the case?" The answer, in turn, is basically "well, if that weird thing didn't happen, then probably the linear increase we see between 3 and 5 would continue." (As sort of a background point, we might also note that the other exception to the linear increase is found between 2 and 3, which corresponds to the jump between s and p orbitals -- so we might generalize this graph as saying "first ionization energies generally increase across groups except for some exceptions that correspond to clear differences in the element's electronic structure").

This pattern is actually fairly common, where a question can be either (a) fairly straightforward if you happen to remember a relatively obscure piece of information in the corresponding content area or (b) answerable based on just the information they give you + one extra logical leap (in this case, making a prediction about a hypothetical situation).

Hope this helps!!

 

[jhmmd]

I believe this involves 2 part substitution

 

[treeclimbingmonkey]

There are two lenses through which you can tackle this: gen chem knowledge and test-taking skills.

From a gen chem standpoint, the idea behind Hund's rule is that an electron is more stable when it has a whole orbital to itself than when it shares an orbital with an electron of opposite spin.

From a test-taking perspective, even if you've never heard of (or have totally forgotten) Hund's rule, this question is essentially saying "something weird happens between N and O, what would happen if that wasn't the case?" The answer, in turn, is basically "well, if that weird thing didn't happen, then probably the linear increase we see between 3 and 5 would continue." (As sort of a background point, we might also note that the other exception to the linear increase is found between 2 and 3, which corresponds to the jump between s and p orbitals -- so we might generalize this graph as saying "first ionization energies generally increase across groups except for some exceptions that correspond to clear differences in the element's electronic structure").

This pattern is actually fairly common, where a question can be either (a) fairly straightforward if you happen to remember a relatively obscure piece of information in the corresponding content area or (b) answerable based on just the information they give you + one extra logical leap (in this case, making a prediction about a hypothetical situation).

Hope this helps!!

Thank you so much!!!

 

[PlsLetMeIn21]

If you draw a straight line from 3 (which has 1 p electron) to 8 (which has 6 p electrons), with energies of 800 (for 3) and 2050 (for 8), then you get 1050 for 4, 1300 for 5, 1550 for 6, and 1800 for 7. Oxygen is 6 (2s22p4 for 6 valence electrons) so you should look for a number around 1550 kJ/mol. It's not 1300 (the number actually shown in the table), so the closest answer is 1700.