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Girls Vs Boys Chemistry Challenge!

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Original post by Kallisto
It depends on the question. Some of them are difficult indeed. Otherwise I give answers, if I can. :tongue:



Would you give a clue, please?


Try researching it first.... I would be horrified if you could answer this straight away!!!
Reply 101
That's a toughie! :eek3:
Original post by BJack
That's a toughie! :eek3:


yay, matched your question then!
Reply 103
Original post by JMaydom
Seeing as this seems to be a bit rigged atm :P I better put some challenging questions in!

Explain why HgO has a distorted structure whereas HgS has a regular (more symmetric) structure.


btw this is way past A-level, but you did ask for challenging questions!!! :P

Does it have anything to do with what is described in this (http://www.massey.ac.nz/~ahermann/Reprints/JPCA_113_12427_2009.pdf) article?
Original post by Wim
Does it have anything to do with what is described in this (http://www.massey.ac.nz/~ahermann/Reprints/JPCA_113_12427_2009.pdf) article?


2 things...

1. this is comparing compounds with different metals
2. do you understand any of it or not? You can't just quote papers at me. Use them to find out the answer.
Original post by JMaydom
(...)
Explain why HgO has a distorted structure whereas HgS has a regular (more symmetric) structure.
(...)


There is an oxide and a sulfide. Could it be that the answer has anything to do with the properties of them?
Original post by Kallisto
There is an oxide and a sulfide. Could it be that the answer has anything to do with the properties of them?


Well yes!

OK a clue is probably in order....

It is due to mixing between anion p orbitals and metal orbitals. This is only possible in a de-symmetrised environment.
Reply 107
Original post by JMaydom
yay, matched your question then!


I think my question was less unreasonable than yours. :indiff:
Original post by BJack
I think my question was less unreasonable than yours. :indiff:


Yeah well nothing wrong with stepping it up a bit! :tongue:
Explain why graphite is able to conduct electricity. :tongue:
Because its hexagonal structure makes it easy for electron to go through it thus conducting electricity.
What is the product of butanol and ethanoic acid?
Reply 111
Original post by ekpenyongnsa
Because its hexagonal structure makes it easy for electron to go through it thus conducting electricity.
What is the product of butanol and ethanoic acid?


Butylethanoate and water.
Original post by ekpenyongnsa
Because its hexagonal structure makes it easy for electron to go through it thus conducting electricity.
What is the product of butanol and ethanoic acid?


Major product: Butyl Acetate
Minor product: H2O
Reply 113
Original post by JMaydom
2 things...

1. this is comparing compounds with different metals
2. do you understand any of it or not? You can't just quote papers at me. Use them to find out the answer.


1. Correct, but is does talk about the structure of mercuryoxide, which is part of your question and could explain this part.
2. Of course I do not understand the article into every detail but I do understand the idea.

I was just asking if this was on the right track to an answer, but I do understand it makes look a bit lazy, sorry for that. I'll try to formulate an answer using your hint.
The expected NMR shift of aromatic protons is around 7-8 ppm. What is the typical shift of protons positioned directly above the centre of a benzene ring, and why does it differ from the normal range?


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Original post by Wim
1. Correct, but is does talk about the structure of mercuryoxide, which is part of your question and could explain this part.
2. Of course I do not understand the article into every detail but I do understand the idea.

I was just asking if this was on the right track to an answer, but I do understand it makes look a bit lazy, sorry for that. I'll try to formulate an answer using your hint.


No I'm not accusing you of being lazy, just saying that it doesn't count as an answer. Sorry but i'm not going to read the whole paper when the abstract implies that the answer isn't in there. The answer I'm looking for isn't anything to do with what the structure of HgO is apart from that it is less symmetric than the structure of HgS.

OK, big clue..... I knew this was going to be needed!!!

The distortion is driven by mixing of the metal and anion orbitals. In the regular structure the anion p cannot interact with the metal levels, it is symmetry disallowed. In the less symmetric environment of the distorted structure the mixing is symmetry allowed.
Now rationalise why this happens for HgO and not HgS!!!

Original post by BJack
I think my question was less unreasonable than yours. :indiff:


It's straight out of lecture notes..... seeing as you're clearly at the same uni as me (given how you know me from somewhere) you should be able to look this up eaisly.
Original post by ekpenyongnsa
Because its hexagonal structure makes it easy for electron to go through it thus conducting electricity.
What is the product of butanol and ethanoic acid?



Original post by PhysicsKid
Explain why graphite is able to conduct electricity. :tongue:


That isn't an answer..... well at least not a correct answer
Original post by PhysicsKid
Explain why graphite is able to conduct electricity. :tongue:


Graphite has unhybridized p orbitals which interact to form a delocalised π\pi - system, so electrons have the ability to move within it.
Original post by Technetium
Graphite has unhybridized p orbitals which interact to form a delocalised π\pi - system, so electrons have the ability to move within it.


:P
Reply 119
Original post by JMaydom
No I'm not accusing you of being lazy, just saying that it doesn't count as an answer. Sorry but i'm not going to read the whole paper when the abstract implies that the answer isn't in there. The answer I'm looking for isn't anything to do with what the structure of HgO is apart from that it is less symmetric than the structure of HgS.

OK, big clue..... I knew this was going to be needed!!!

The distortion is driven by mixing of the metal and anion orbitals. In the regular structure the anion p cannot interact with the metal levels, it is symmetry disallowed. In the less symmetric environment of the distorted structure the mixing is symmetry allowed.
Now rationalise why this happens for HgO and not HgS!!!



It's straight out of lecture notes..... seeing as you're clearly at the same uni as me (given how you know me from somewhere) you should be able to look this up eaisly.



I'm pretty sure that you can prove these sorts of distortions are always lead to a reduction of the p orbital energy (due to the lowering in energy of the occupied p orbitals). However whether or not the distortion occur depend on whether this outweighs the increase in energy of the other interactions. Whether this will occur depends on the strength of the other Hg-O/S interactions. You'd expect Hg-S interactions to be stronger than Hg-O (due to the energies of the bonding electrons) and so the distortion would not be favoured in Hg-S.

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