I am pretty sure i put +41 as well... can't remember lmao, and yes yes photochemical smog is probably what they wanted, the smoke affect seen by zinc is due to the fact that it will be like particulates in the air
These were my calculation answers, in order of how they appeared in the q paper Mass of air: 834.7 Mass of air for 1g of C4H10O: 11.28 Energy Density: 36200 Hess' Law: +41 KNOW: 34.15%
Not sure if theyre right but lemme know if you got the same/different
literally got the same... i rounded my answers to less significant figures though depending on the question... i found the calculations in this paper very friendly
I got the paper if anyone would like a question/marks. Also my chemistry teacher said that they don't take into account the previous years paper at all (he marks for OCR). The boundaries depend on how well everyone does because they set them based on that.
Yeah I thought they do, but considering say last year both AS and A2 retakers sat the exam, so a larger proportion may have gotten lower grade, yet this year it is entirely A2 taking the exam and there's less so the grade boundaries won't be dragged down, and they are more likely to know because they've built on it, I think it'd be unfair but oh well the grade boundaries won't be too crazy
I thought if 75% or whatever is Kno3 then 75/mr should give me the percentage of moles ? I dunno
Will i get alteast 1 mark?
you had to almost assume overall 100 percent of the substance is 100g, work out the moles of each different component of the substance using percentage divided by mr. sum of all of these values would give u total moles. then take a percentage of moles of KNO3. hopefully i am making sense
Wassup fellow retakers , bit late to the thread buuut some important stuff. Ill get to the important stuff first.
Important? So i messed up revision for this and was only able to do a few past papers, hoping i'd see a trend, i did the even number years ONLY, so 2012 Jan/Jun and 2014. With my luck, turns out 2016 paper was VERY similar to them three. Not sure if same will apply for further units but its good to know i guess
My thoughts on the paper: I think i did well on this exam...too well 👀, since ive done this exam twice before, i thought i got an A twice, didnt. But i dunno, im feeling something good about this exam, seems super easy and majority of my answers were the same as others. Im guessing a 47-50 for an A. Theory questions were straight forward, maths were hell.
For the metallic bonding question did you have to put Mg2+ and Al3+? Or could you just write magnesium/aluminium ion, seeing as though the charges were in the diagram that the labels were pointing too