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Edexcel A2 Chemistry Unit 5 (CH05) - 24 June 2011

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The final hurdle, organic nitrogen compounds I have 2 hours to revise it!

And then I'm done...
Original post by Stratos
The final hurdle, organic nitrogen compounds I have 2 hours to revise it!

And then I'm done...


hahaha better get to it
Reply 1962
Avatar for jay110
jay110
2
Original post by Stratos
The final hurdle, organic nitrogen compounds I have 2 hours to revise it!

And then I'm done...


Just need to do my Amino Acids chapter and then I'm done :smile:
Morning guys..... Plz plz. I need help :smile:

1) I have a real problem in moles questions.. If you solved June 2010 and Jan 2011 its almost same que.. Or same way to get solution... Can somebody summarize it?


2) how can I be a synthetic routes proffessional? Plz :frown:
Anyyyyyybodyyyyyy :frown: I have to go sooooooooon
Reply 1965
Avatar for SK-mar
SK-mar
1
morning people.... im getting confused with zinc complexes as the cgp says differently to what other people are saying:

for water it is : Zn(H2O)6^2+
but for drops of OH- it is Zn(H20)3(OH)3 in cgp , but i thought it was Zn(H2O)2(OH)2 ???

and for ammonia / excess OH it has 6 ligands, but i only thought it had 4?
Good luck guys!!
Original post by abuelzouz
Morning guys..... Plz plz. I need help :smile:

1) I have a real problem in moles questions.. If you solved June 2010 and Jan 2011 its almost same que.. Or same way to get solution... Can somebody summarize it?


2) how can I be a synthetic routes proffessional? Plz :frown:


Please
Original post by abuelzouz

Original post by abuelzouz
Please


We question on moles? :s-smilie:

Synthetic route:
Many steps- less yield produced
Therefore, least desirable method.
Original post by imaam
Thanks again.


Can you please draw it in paint or other and stick it on here?.. It would aid your revision and it would sure as hell help me understand what it is you just described so beautifully?? :frown: please please please :smile:
Original post by SK-mar
morning people.... im getting confused with zinc complexes as the cgp says differently to what other people are saying:

for water it is : Zn(H2O)6^2+
but for drops of OH- it is Zn(H20)3(OH)3 in cgp , but i thought it was Zn(H2O)2(OH)2 ???

and for ammonia / excess OH it has 6 ligands, but i only thought it had 4?


wouldnt it be ZN(h20)4(0h)2 ?
Reply 1971
Avatar for ophtho
ophtho
7
Original post by SK-mar
morning people.... im getting confused with zinc complexes as the cgp says differently to what other people are saying:

for water it is : Zn(H2O)6^2+
but for drops of OH- it is Zn(H20)3(OH)3 in cgp , but i thought it was Zn(H2O)2(OH)2 ???

and for ammonia / excess OH it has 6 ligands, but i only thought it had 4?


for excess OH it has six probably because zinc is amphoteric dunno youre right about the first bits though it should be two
Right. A few questions to boggle your minds.

1> Outline steps how you can identify amino acids.
2> Write the equation for the formation of paracetamol.
3>Why do azo dyes make good dyes? What colour is the one we need to know about.
4> What is the colour and formula of Zinc in excess OH- ions?
5> Differentiate why methoxybenzene and phenol are better reactants than benzene.
Original post by SK-mar
morning people.... im getting confused with zinc complexes as the cgp says differently to what other people are saying:

for water it is : Zn(H2O)6^2+
but for drops of OH- it is Zn(H20)3(OH)3 in cgp , but i thought it was Zn(H2O)2(OH)2 ???

and for ammonia / excess OH it has 6 ligands, but i only thought it had 4?


coordination number for both H2O and OH is 6 So I would assume it would form Zn(H2O)4(OH)2 as a precipitate, and zink is always colourless.
The coordination number depends on the size of the molecule so for chlorine its 4, since it's larger than H20 and NH3 which are each 6.
(edited 12 years ago)
Original post by bertstare
wouldnt it be ZN(h20)4(0h)2 ?


You are right, CGP made a typo. Confirmed with my teacher.
Original post by EricEdwardSelvaraj
Right. A few questions to boggle your minds.

1> Outline steps how you can identify amino acids.
2> Write the equation for the formation of paracetamol.
3>Why do azo dyes make good dyes? What colour is the one we need to know about.
4> What is the colour and formula of Zinc in excess OH- ions?
5> Differentiate why methoxybenzene and phenol are better reactants than benzene.


1) paper chromatography and ninhydrin, rf values and ting
2) its ethanoyl chloride plus a phenol with an amine group i think
3) stable due to N=N system so do not fade, theyre orange i think
4) colourless,
5) donates electrons to delocalised system, increased density
What the hell is deprotonation? I will rep you for life if u can give me the simples version of this is
Reply 1977
Avatar for SK-mar
SK-mar
1
Original post by EricEdwardSelvaraj
You are right, CGP made a typo. Confirmed with my teacher.


so what is it with excess OH- and excess ammonia???

Zn(OH)4 or Zn(H2O)2(OH)4

and for ammonia is it Zn(NH3)4 or Zn(NH3)4(H2O)2 ???
Original post by bertstare
1) paper chromatography and ninhydrin, rf values and ting
2) its ethanoyl chloride plus a phenol with an amine group i think
3) stable due to N=N system so do not fade, theyre orange i think
4) colourless,
5) donates electrons to delocalised system, increased density


Generally correct.

1> React with ninhydrin, produces ammonia and hydindatin which react with more ninhydrin to form ruhemann's purple.
2) yes, its called p-aminophenol
3) yup
4) colourless, of course coordination number of zinc is 4 in excess OH- and excess NH3
5) methoxy benzene and methyl benzene donate electrons, but the p oribital of the oxygen in phenol overlaps with benzene ring - different!
Original post by SK-mar
so what is it with excess OH- and excess ammonia???

Zn(OH)4 or Zn(H2O)2(OH)4

and for ammonia is it Zn(NH3)4 or Zn(NH3)4(H2O)2 ???


Zn(OH)4 coordination number changes for unknown reason, lets just learn it

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