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Aqa chem 4/ chem 5 june 2016 thread

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What was the C peak number? I put 8 but apparently its wromg
Also for the 3 marker on the percentages, did you have to divide each number by the mr (I think 118) and then multiply by 100 then all the percentage answers added up to 100?
Unofficial MS anywhere?
Original post by jammypancake
What was the C peak number? I put 8 but apparently its wromg


We're pretty certain it's 9
Original post by HannahC-H
It was three marks: One for the reagent, one for observations with each


**** ffs such a daft mistake like
Thinking of sending AQA this, but with examples and that:

This exam was disproportionately difficult. Not because of the application questions or even question 9, which were difficult, but because of the horrible questions worth few marks that took too long, leading to the last half being rushed and allowing NO opportunity to check through, which you (AQA) yourselves advise us to do, then don't allow us to. I noticed immediately it was strange, as the timing recommended was 80 minutes for section A and 25 minutes for section B, which differs from past papers, and was unrealistic. Truly ridiculous AQA - your choice of questioning will have devastating consequences on the futures of many young people, and definitely did not reward hard work or revision, or even merit knowledge of the A level Chemistry specification. The ONLY way to rectify this situation is to lower the grade boundaries.
(edited 7 years ago)
Original post by cookiemonster15
That paper was literally ridiculous. The style of it seemed so different to the previous years, that, and the fact that the wording of the questions were so awkward, I had to read the stem of the questions (especially all those one and two markers) so many times before I could actually figure out what they were saying!

And the worst thing was, I was feeling so ready for this exam which is actually so very rare. I had gone through every single thing in the book and looked at so many past papers, I went in thinking that there was only so much that they could do to make CHEM4 harder. *Snorts* Yeah right.

I knew all my mechanisms inside out, I spent so long memorising them and drawing them all out, figuring out which mechanism corresponds with which compounds. I knew my equilibria - one of the few topics that I was actually quite confident on. I had finally figured out how to find the rate determining step. After months of practice, I could work out the PH of buffer without a problem. I knew my nitration equations, I knew my Friedel-Crafts and my acylation reactions. And did any of that come up?



uh.......no.



Waste of a year. Thanks AQA, I appreciate that.

And here I thought that the exam was actually going to be alright.

(I swear to god, Biology on thursday better not be this bad)

I feel exactly the same :frown:
Original post by jessyoung
∆G+T∆S=∆H
T∆S= ∆H-∆G
Then divide ∆H-∆G by T to give you ∆S :smile:



Thanks :smile: What if they asked for ∆H though would that be (∆S - ∆G) / T?
Original post by cookiemonster15
I know what you mean but could you give an example question so it would be easier to explain?


Yeah it's from June 14 exam
When Silver Fluoride dissolves in water at 25 degrees, the free energy change is -9 kJ mol-1. Use this info and data from table 2 to calculate a value with units for the entropy change when silver fluoride dissolves in water at 25 degrees.

so ∆G = -9
∆H = -15
T = 298

How do I rearrange it to get ∆S on the left hand side is what I'm asking and is there a certain way of doing it because I have no idea haha
Original post by Owensmith16
Thinking of sending AQA this, but with examples and that:

This exam was disproportionately difficult. Not because of the application questions or even question 9, which were difficult, but because of the horrible questions worth few marks that took too long, leading to the last half being rushed and allowing NO opportunity to check through, which you (AQA) yourselves advise us to do, then don't allow us to. I noticed immediately it was strange, as the timing recommended was 80 minutes for section A and 25 minutes for section B, which differs from past papers, and was unrealistic. Truly ridiculous AQA - your choice of questioning will have devastating consequences on the futures of many young people, and definitely did not reward hard work or revision, or even merit knowledge of the A level Chemistry specification. The ONLY way to rectify this situation is to lower the grade boundaries.


Be sure to Sign the petition!

http://www.ipetitions.com/petition/lower-grade-boundaries-for-chemistry-unit-4-2016
Reply 1590
Guys the acylium ion question i swear the ion was different on the benzene ring it had a Cl attached to it! So the ion should have looked different right?? Please reply cuz i added a cl to the structure
Original post by Ebaysass
Guys even if you feel the paper was fine, even if you feel like you don't care or even if you feel this might not actually do anything, its still worth a try.....

give this and look and signnnnnnn it!!!!!!!

http://www.ipetitions.com/petition/lower-grade-boundaries-for-chemistry-unit-4-2016

and share it with everyone, the more awareness the better!!


Can everyone sign this please :bawling:
Original post by 26december
Thanks :smile: What if they asked for ∆H though would that be (∆S - ∆G) / T?


so ∆G=∆H-T∆S
And ∆H= ∆G+T∆S
Always best to start from the original equation :smile:
Original post by Anam
Guys the acylium ion question i swear the ion was different on the benzene ring it had a Cl attached to it! So the ion should have looked different right?? Please reply cuz i added a cl to the structure


Yeah I had a cl on mine too! it was different to just a normal electrophilic sub mechanism
Original post by Anam
Guys the acylium ion question i swear the ion was different on the benzene ring it had a Cl attached to it! So the ion should have looked different right?? Please reply cuz i added a cl to the structure


You are right, there was a Cl, it was something like ClCH2CHO and so the ion was ClCH2CO+ or something
Original post by Owensmith16
how many marks would that test for acycl chloride be worth...i didnt see the cl so did tollens reagent instead, stupidly


Ah **** I did the same thing, I remember seeing it first and thinking silver nitrate and stuff but I left it and came back to it and forgot about the chloride
I could have sworn the question about suggesting a new rate equation said the conc of h+ and I2 was increased by ×100 so i put the new rate equation as r=k[propanone] bc propanone is limiting factor??
Original post by bluhbluhbuh
this helps, i'll remake it in this format, might remember a few


Do you remember what the moles were ?
Does anyone know what the moles were for the ethanoic acid/water/salt/some thing else
In order to work out Ka in 310cm3
Whats the Predictions for a grade C :s

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