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AQA CHEM2 ~ May 23rd 2012 ~ AS Chemistry

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hey :smile: Can someone help me with the extractions of copper, what two ways do we need to know.
I'm so confused I get something to do with so2 when I goggle it, but then theres something about cuco3 --> cuo + co2, then 2cuo +c -->230z, and something about

using scrap
iron to extract copper from aqueous solutions compared
with the high-temperature carbon reduction of copper oxide

thanks in advance
how many ums are both Chem1 and Chem2 worth each?
thanks in advance x
Original post by AishaTara
how many ums are both Chem1 and Chem2 worth each?
thanks in advance x


Chem 1 = 100
Chem 2 = 140

For future reference, the details are in the syllabus, which you can get from the AQA website. :smile:
Original post by Doctor.
!


hey Can someone help me with the extractions of copper, what two ways do we need to know.
I'm so confused I get something to do with so2 when I goggle it, but then theres something about cuco3 --> cuo + co2, then 2cuo +c -->230z, and something about

using scrap
iron to extract copper from aqueous solutions compared
with the high-temperature carbon reduction of copper oxide

thanks in advance
(edited 12 years ago)
Original post by AishaTara
hey Can someone help me with the extractions of copper, what two ways do we need to know.
I'm so confused I get something to do with so2 when I goggle it, but then theres something about cuco3 --> cuo + co2, then 2cuo +c -->230z, and something about

using scrap
iron to extract copper from aqueous solutions compared
with the high-temperature carbon reduction of copper oxide

thanks in advance


check page 12 for the equations and explanations.
Original post by cuckoo99
hoping to do a chemistry related degree at uni or just chemistry ;p;p


^5

In all honesty I empathise with you. 2 of my amigos who love the subject got U's themselves when they didn't deserve them (heck, I even got a C in physics)

I'm sure you'll be fine this time. If you focus on what you need to improve on and get any support you need you should be cool. Don't neglect unit 2 though.
Original post by Silverland
^5

In all honesty I empathise with you. 2 of my amigos who love the subject got U's themselves when they didn't deserve them (heck, I even got a C in physics)

I'm sure you'll be fine this time. If you focus on what you need to improve on and get any support you need you should be cool. Don't neglect unit 2 though.


thanks :smile: i was geting B's in my class mocks so i'm pretty sure im ok with content, though ofc im gunna go over all the content again as there are certain areas that need improvment. dont worry i dont intend to neglect unit 2 ;p its a very important unit( that that the others aren't) but in terms of ums its very important
Hey people :smile: just wondering what do we need to know for polymerisation :smile: the aqa book is really vague...
Also, when concentrated sulphuric acid is reacted with iodide; iodine acts as a reducing agent and the three products produced are sulphur, so2, and h2s, does anyone know the redox equations for so2, and S as the aqa textbook only states the one for hs2, but does say we need to know the other two.
thanks in advance xx
Heya,

I don't think we need to know much at all as it is not that relevant in my opinion. I need to really start revising properly LOL. The textbook is really bad :smile: I find redox really hard and half equations :s-smilie:

Jim
Original post by AishaTara

Also, when concentrated sulphuric acid is reacted with iodide; iodine acts as a reducing agent and the three products produced are sulphur, so2, and h2s


In the textbook it will likely only show the following:

H2SO4(l) + 8I- + 8H+ -> H2S(g) + 4H2O(l) + 4I2(s)

This is because iodide ions are good reducing agents and so it will reduce all the way through to hydrogen sulfide.

What have you tried for the redox equations for S and SO2? I could tell you what you want to know, but I feel it is always better for someone to try it for themselves first so we can understand where you may be going wrong.
Original post by Tullia
In the textbook it will likely only show the following:

H2SO4(l) + 8I- + 8H+ -> H2S(g) + 4H2O(l) + 4I2(s)

This is because iodide ions are good reducing agents and so it will reduce all the way through to hydrogen sulfide.

What have you tried for the redox equations for S and SO2? I could tell you what you want to know, but I feel it is always better for someone to try it for themselves first so we can understand where you may be going wrong.


Hey :smile: thank you, I've got the first equation and I understand it, but the second two I'm not sure:

2H+ 2I- + H2SO4 --> So2 + 2H20 + I2
and

no idea for the second one :/
Original post by aishatara
hey :smile: thank you, i've got the first equation and i understand it, but the second two i'm not sure:

2h+ 2i- + h2so4 --> so2 + 2h20 + i2
and

no idea for the second one :/


Acid-base reaction:

h2so4 + i- -> hso4- + hi

Reduction to sulfur dioxide:

h2s04 + 2h+ + 2i- -> s02 + 2i2 + 2h20

Reduction to sulfur:

h2so4 + 6h+ + 6i- -> s + 3i2 + 4h2o

Reduction to hydrogen sulfide:

h2so4 + 8h+ + 8i- -> h2s + 4i2 + 4h2o
Has anyone got the chemistry unit2 january 2012 question paper??????
I would be grateful if you could upload it
thanks,
God revision for this is such an effort :erm:
Definitely underestimated how much time this unit would take to revise!
Original post by Tullia
Acid-base reaction:

h2so4 + i- -> hso4- + hi

Reduction to sulfur dioxide:

h2s04 + 2h+ + 2i- -> s02 + 2i2 + 2h20

Reduction to sulfur:

h2so4 + 6h+ + 6i- -> s + 3i2 + 4h2o

Reduction to hydrogen sulfide:

h2so4 + 8h+ + 8i- -> h2s + 4i2 + 4h2o


thank you :biggrin: but the reduction or sulphur dixoide, isn't balanced. you've got 2I on one side, but 2i2 on the other :/
thanks for the others though :biggrin: very grateful
hey all, when are you starting past papers, when you've finished fully revising or now? I was thinking am I leaving it too late...:/
Original post by AishaTara
thank you :biggrin: but the reduction or sulphur dixoide, isn't balanced. you've got 2I on one side, but 2i2 on the other :/
thanks for the others though :biggrin: very grateful


It's a typo. And no worries.
Original post by Tullia
It's a typo. And no worries.


:smile: I was also wondering do you know what we need to know for polymerisation- i find the textbooks pretty vague, as well as the mark scheme :/
thanks
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Part A
18
Planning to do 2 chapters a day for this unit, will have done 4 chapters/11 by the end of today.
Almost a week into the holidays and not even got through a full booklet. Awww yiss.
Hardcore revision starts tomorrow :tongue:

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