Unit5/unit 4 chemistry - EDEXCEL June 2012
Chemistry exam discussion - share revision tips in preparation for GCSE, A Level and other chemistry exams and discuss how they went afterwards.
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Re: Unit5/unit 4 chemistry - EDEXCEL June 2012yeah i did the calculation and it seemed such a big negative number for delta H solution, but i looked back at the data booklet and it said -U at the top so i was like 'yeahhhhhh budddy'. The answer i then got was more sensible!(Original post by Liam 09)
I think the hess cycle calculation was actually +12 not a large negative number. The lattice enthalpies in the data booklet were all stated as positive numbers, but they are actually negative numbers, and at the top it said something like -U which meant take the lattice enthalpies as negative numbers, and if you did that, you actually get +12 instead of the large negative number. -
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Re: Unit5/unit 4 chemistry - EDEXCEL June 2012Yeah sodium thiosulfate(Original post by TL1)
What reagent did you all get to titrate with Iodine on the zero order page? I put Sodium Thiosulfate? -
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Re: Unit5/unit 4 chemistry - EDEXCEL June 2012I just remember a past paper question saying lattice enthalpy of MgCl2 was like a large negative number, and the data booklet said the same number, but positive, so I just assumed they were all meant to be negative and noticed the -U later :P(Original post by James A)
yeah i did the calculation and it seemed such a big negative number for delta H solution, but i looked back at the data booklet and it said -U at the top so i was like 'yeahhhhhh budddy'. The answer i then got was more sensible!
Also the fact that +12 is much more similar to the +3 given for the other compound in the next question. -
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Re: Unit5/unit 4 chemistry - EDEXCEL June 2012http://www.thestudentroom.co.uk/show....php?t=2031550(Original post by demdil)
heyy someone gave a link to a new unit 5 chem thread for the exam on tuesday .. can someone give the link again? -
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Re: Unit5/unit 4 chemistry - EDEXCEL June 2012i didnt realized the -U. FML. Byebye A(Original post by Liam 09)
I just remember a past paper question saying lattice enthalpy of MgCl2 was like a large negative number, and the data booklet said the same number, but positive, so I just assumed they were all meant to be negative and noticed the -U later :P
Also the fact that +12 is much more similar to the +3 given for the other compound in the next question.
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Re: Unit5/unit 4 chemistry - EDEXCEL June 2012wasn't it +13?(Original post by Liam 09)
I just remember a past paper question saying lattice enthalpy of MgCl2 was like a large negative number, and the data booklet said the same number, but positive, so I just assumed they were all meant to be negative and noticed the -U later :P
Also the fact that +12 is much more similar to the +3 given for the other compound in the next question.
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Re: Unit5/unit 4 chemistry - EDEXCEL June 2012if 100 UMS.. i think roughly around 75/90(Original post by Thectan)
Ouch mate.. I think I'm looking at about 100 UMS? For 77/80 roughly?
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Re: Unit5/unit 4 chemistry - EDEXCEL June 2012really? thats so low! how hard did you find the paper?(Original post by kanasaki)
if 100 UMS.. i think roughly around 75/90 -
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Re: Unit5/unit 4 chemistry - EDEXCEL June 2012by 100 UMS do you mean full marks (120/120) because 75/90 giving 100/120 is quite high(Original post by kanasaki)
if 100 UMS.. i think roughly around 75/90 did you find the paper easy?
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Re: Unit5/unit 4 chemistry - EDEXCEL June 2012I think it will be.(Original post by Thectan)
I found it doable but not too easy... Needless to say I think I got about 77/90 which I'm hoping is over 108UMS
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January 2012 was not as difficult as this paper, and the grade boundaries were 75/90 for an A*. -
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Re: Unit5/unit 4 chemistry - EDEXCEL June 2012My estimation is(Original post by zincoff)
I think it will be.
January 2012 was not as difficult as this paper, and the grade boundaries were 75/90 for an A*.
69 for an A
73 for an A*
i reckon i got 79/90 marks which should definitely be above 108 ums... -
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Re: Unit5/unit 4 chemistry - EDEXCEL June 2012I agree with the A* mark being around 73-74, not with the A.(Original post by James A)
My estimation is
69 for an A
73 for an A*
i reckon i got 79/90 marks which should definitely be above 108 ums...
Historically, the grade boundaries for Chemistry aren't narrow like in Biology and are usually 7-8 marks in between.
I think the mark for an A will be 66 or 67/90, give or take one or two marks.
I'm not sure how I did to be honest and I don't want to be too sure either, I knew the paper was challenging and harder than some of the past papers whilst I was doing it but I was well prepared so I answered questions without too much trouble. But likewise I'm hoping for above 108 UMS
. Fingers crossed for us haha
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Re: Unit5/unit 4 chemistry - EDEXCEL June 2012I think a titration question will be on the paper. Most Unit 5 papers are mainly organic, all of the organic material is synoptic so it comes up a lot.(Original post by TL1)
I think there will be a large section on Electrode Potentials. Last paper was seriously organic
and I need the A...
