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OCR 21st Century Science C4 C5 C6 14th June 2016 Discussion thread

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Original post by NiamhM1801
Oh for THAT one...I thought they were on about a different question.
I think you were meant to put symbols yeah, did anyone else get Be and B?


Yup, I wrote that.
Original post by BULL14
The last question about isolation - was left,middle,right
The products of silver chloride was chlorine
The answer to the silver chloride word equation.- ?
The question about endothermic and exothermic reactions - label the graphs and which reaction corresponded to which graph and draw the energy levels and say exo... gives energy to surrounding or vice versa.
I hope this helps


I think the word equation was silver nitrate + sodium chloride ----> silver chloride+ sodium nitrate...
Something similar to that.
Original post by Deliciate
I think the word equation was silver nitrate + sodium chloride ----> silver chloride+ sodium nitrate...
Something similar to that.



everyone one for other exam boards have a mark scheme. I really think we should get together and collaborate on each others' answers and make one ourselves.
Original post by BULL14
everyone one for other exam boards have a mark scheme. I really think we should get together and collaborate on each others' answers and make one ourselves.


yeah i agree
Has anyone made a P4, P5, P6 thread? :h:

I'm so nervous for physics..
will they mark me down for writing the elements instead of symbols ? So beryllium and boron instead of Be and B ?
Original post by andreeac
will they mark me down for writing the elements instead of symbols ? So beryllium and boron instead of Be and B ?


Potentially, I think they wanted you to write the symbols specifically, you know how fussy OCR are. That being said, still be optimistic because they may still accept both or perhaps give you one mark. I doubt they'll be that harsh to deduct two marks away simply because you wrote the elements. Don't stress over it though because there's no point asking for what OCR will accept or discard on this site, only time will tell.
Original post by BULL14
everyone one for other exam boards have a mark scheme. I really think we should get together and collaborate on each others' answers and make one ourselves.


agreeing on that!! can't find an ocr one anywhere
Original post by NiamhM1801
Well yeah, but both of them apparently had a charge of 2? Which would not have made sense seeing as how there were 2 Bromine atoms and only 1 Lead atom (and they have to balance)

The correct half equation makes no sense to me at all.


There are two bromine atoms and one lead atom in the molecule, and they told you that Bromine ions were 1-, therefore the two bromine atoms in the molecule must have had a charge of 1- each, for a total of 2- (2 * 1- = 2-). Therefore the lead atom must have had a charge of 2+, in order to cancel out the 2- of the bromine.

The confusing part (and this confused me too) is that lead is in group four, so has four outer shell electrons, so should form a 4+ (or 4- or whatever) ion. I looked it up and there's some very complex in depth answer as to why this is not the case, but I didn't understand it at all and at GCSE level they don't expect us to - they just expected us to look at the 2 x 1- charges of the bromine and figure out that lead must be 2-.

But, this is why the question was ridiculous - I'm sure almost all of us have been taught that a way to figure out what the charge on an ion is is to look at the group number in the periodic table, and this didn't work at all for this question because of reasons that we can't possibly understand at a GCSE level.

I didn't understand this at all until reading through a ton of things earlier, but I managed to get the right answer through misunderstanding the question in a way that happened to be right, which is... good I suppose :redface:

TL;DR OCR's question was stupid and everyone was right to be confused
Guess what, the element question asked for the elements of the atomic number ___ 11 and ___ so it was fluorine and another one. I forgot.
Well.... I did not get Be and B for that periodic table.. So I might have lost those marks. I can't even remember what I got anyway
Original post by KomradeKorbyn
There are two bromine atoms and one lead atom in the molecule, and they told you that Bromine ions were 1-, therefore the two bromine atoms in the molecule must have had a charge of 1- each, for a total of 2- (2 * 1- = 2-). Therefore the lead atom must have had a charge of 2+, in order to cancel out the 2- of the bromine.

The confusing part (and this confused me too) is that lead is in group four, so has four outer shell electrons, so should form a 4+ (or 4- or whatever) ion. I looked it up and there's some very complex in depth answer as to why this is not the case, but I didn't understand it at all and at GCSE level they don't expect us to - they just expected us to look at the 2 x 1- charges of the bromine and figure out that lead must be 2-.

But, this is why the question was ridiculous - I'm sure almost all of us have been taught that a way to figure out what the charge on an ion is is to look at the group number in the periodic table, and this didn't work at all for this question because of reasons that we can't possibly understand at a GCSE level.

I didn't understand this at all until reading through a ton of things earlier, but I managed to get the right answer through misunderstanding the question in a way that happened to be right, which is... good I suppose :redface:

TL;DR OCR's question was stupid and everyone was right to be confused


I agree it was stupid as my default way is to go to the periodic table!

And I swear it said that bromine's charge was 2- (I know it's not meant to be but that's what I read and I wasn't thinking straight), although I probably read it wrong. Meh, it was like 1 mark anyway
Reply 192
Original post by realsmilee
Has anyone made a P4, P5, P6 thread? :h:

I'm so nervous for physics..


This thread is for all the physics

http://www.thestudentroom.co.uk/showthread.php?t=4067103&page=8&p=65817579#
(edited 7 years ago)
Reply 194
Hmmm (sorry for the delay)...

The compound on someone's sunglasses was AgCl, when sunlight hit the lense, the lense turned darker due to a chemical reaction happening. One formation was the metal Silver,

What was the OTHER element formed?
Reply 195
Original post by Will8
Hmmm (sorry for the delay)...

The compound on someone's sunglasses was AgCl, when sunlight hit the lense, the lense turned darker due to a chemical reaction happening. One formation was the metal Silver,

What was the OTHER element formed?


I put chlorine
Original post by Ben.M
I put chlorine


Original post by Will8
Hmmm (sorry for the delay)...The compound on someone's sunglasses was AgCl, when sunlight hit the lense, the lense turned darker due to a chemical reaction happening. One formation was the metal Silver,What was the OTHER element formed?

I put chlorine too, not sure what else it could've been.

The equation they gave you was essentially "AgCl ----> Ag + ____" and since there was nothing else except Cl it had to be chlorine being formed. The reaction was just the sunlight's heat breaking apart the AgCl molecule into Ag and Cl, I think.
Original post by BULL14
The last question about isolation - was left,middle,right
The products of silver chloride was chlorine
The answer to the silver chloride word equation.- ?
The question about endothermic and exothermic reactions - label the graphs and which reaction corresponded to which graph and draw the energy levels and say exo... gives energy to surrounding or vice versa.
I hope this helps


Am I REALLY the only one who put right, middle, right on the isolation question?
Original post by mupsman2312
Am I REALLY the only one who put right, middle, right on the isolation question?


The top one could only have been left - sodium chloride can't be filtered out of a solution as it is soluble.
What do you think the grade boundaries will be?


Last yr was 40 for an A*

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