Chemistry Exam Predictions/Thoughts (1 Viewer)

Siwel

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It was hard, but if youve done 2020 it wasnt a curveball, pretty similar in terms of the types of questions. Altho it was a bit of a pisstake with module 8, and 7. The whole exam was just mod 5 and 6 having a baby.
literally a blessing mod 7 and 8 is terrible, but definitely more of a maths paper (if you do standard maths itll be rough)
 

Jojofelyx

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everyone i know said it was hard and they were good at chem. unless you guys are on another level
It was hard, i dont think it was much harder than last year though, and last years cut off was 80/81, so i assume itll stay the same. Then again, it was on here that someone said that people tend to overestimate their marks, and science markers are really picky with things too so i wouldnt be surprised if it creeped down to like 78-79 for a b6.
 

Jojofelyx

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were we doing the same paper, it was not all maths lol there were maths questions but it was definitely not that calculation heavy
Well all of the harder questions were calcs so that might be where my bias lies
 

Greninja340

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For this question i used 2,3,4 for my titration calculation but PEAK solutions only used 2,4 so would this mean i lose a mark or is it not that big of a deal?
 

CM_Tutor

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For this question i used 2,3,4 for my titration calculation but PEAK solutions only used 2,4 so would this mean i lose a mark or is it not that big of a deal?
Titre 1 is clearly a rough titration and should be discarded. I would penalise including it in finding the average volume.

With regard to the rest, proper technique is to repeat until 3 concordant values are obtained, this being three values with a range of no more than 0.1 mL. So, PEAK are taking the approach that the only pair with a range of up to 0.1 mL is titres 2 and 4. The problem is that this is not 3 values. If this were a practical exam, I would penalise the student for not continuing until they had 3 concordant values, but not penalise the calculation based on just 2 and 4 or instead using 2, 3, and 4. Neither is strictly justifiable because one lacks concordancy and the other lacks 3 values. Since this an exam question about processing data, I would accept either approach, though I would hope that students would note the choice that they are making and the reason for it - but I am sure that most won't.

So, yes, it is a bit of a big deal but the problem lies in the data itself, not in the choice made about how to process it. Either approach to the analysis is justifiable in the circumstances. Best practice would be to expressly state the choice made and the reason for it, but it is unrealistic to expect that at this level. What I would penalise is including titre 1 because that is an analytical error.
 

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