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AQA GCSE Chemistry - C2 & C3 (14th May 2015)

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I just want to say to everyone don't keep your hopes too high about the grade boundaries being lowered. These tests were being made hard ON PURPOSE as too many people were getting a stars. Internationally GCSEs are frowned upon by other countries as gcse were seen to be easier. Therefore to increase the value of the gcse, they have made the tests harder and they would also keep the grade boundaries high as they don't want so many people getting a stars! They want to separate the brightest from the bright.
Original post by Jamesosborne
Bonding between sodium and chloride ? Did anyone write that sodium gives an electron to chlorine so it has a positive charge and chlorine gains it and becomes negative both have a full outer she'll?


I put all of that basically and then after that I put that the negative chlorine ion attracts to the positive sodium ion


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Original post by kevinspl2000
im in year 10 im doing unit 1 2 and 3 of biology and chemistry. Im doing physics next year. I really hope for 2 A*'s however i am ambivalent as to whether I will actuarly get this. what colledge are you applying to?


wow in year 10???! you must be clever. I'm going xaverian college in manchester :smile:
Please can someone make a C3 mark scheme?x
For c3 the last question
The volume was 30cm3.
The temperature change was 20°c (maximum temp(38°c) - initial temp(18°c)).
The energy release was 30Ă—4.2Ă—20= 2520J
Original post by 123456789s
For c3 the last question
The volume was 30cm3.
The temperature change was 20°c (maximum temp(38°c) - initial temp(18°c)).
The energy release was 30Ă—4.2Ă—20= 2520J


it said total volume, so it must have been 25+30 = 55cm^3
temp change was overall temp change, so you compare last measurement to first measurement and i got 14.

55*4.2*14 = 3234J
Original post by Theawesomejem
wow in year 10???! you must be clever. I'm going xaverian college in manchester :smile:

I had to teach most of unit 2 and 3 myself as I was initially put into the foundation class :tongue:. I went to the teacher and he said I need to learn unit 2 and 3 so I did and got in :smile: most of my school is full of stupid people as it's not grammar. I really regret not applying to a grammar school :l
The answer is 2520J
Original post by kevinspl2000
I had to teach most of unit 2 and 3 myself as I was initially put into the foundation class :tongue:. I went to the teacher and he said I need to learn unit 2 and 3 so I did and got in :smile: most of my school is full of stupid people as it's not grammar. I really regret not applying to a grammar school :l


Trust me a grammar school is not much better!
oh no it didn't say describe what happens when sodium reacts with chlorine so i didn't talk about lose/gain of electrons :s it said whats the structure or something. i put giant lattice containing oppositely charged ionic bonds held together by strong electrostatic forces which require lots of energy to break. Do you think that would be ok?
Original post by Theawesomejem
oh no it didn't say describe what happens when sodium reacts with chlorine so i didn't talk about lose/gain of electrons :s it said whats the structure or something. i put giant lattice containing oppositely charged ionic bonds held together by strong electrostatic forces which require lots of energy to break. Do you think that would be ok?


That would be a strong 4/5 marks
Original post by Blueyy__
it said total volume, so it must have been 25+30 = 55cm^3
temp change was overall temp change, so you compare last measurement to first measurement and i got 14.

55*4.2*14 = 3234J


That's what I thought at first but I checked with my teacher after the exam and said it was correct as they are measuring the temperature increase and if the reaction carried on the end temp woulove been 18 making the answer 0 so it didn't make sence.
Original post by Theawesomejem
oh no it didn't say describe what happens when sodium reacts with chlorine so i didn't talk about lose/gain of electrons :s it said whats the structure or something. i put giant lattice containing oppositely charged ionic bonds held together by strong electrostatic forces which require lots of energy to break. Do you think that would be ok?


I put that and emailed my teacher and he said that its fine and the mark scheme will offer a range of answers xx
I used 29cm3. And got 2436J I hope there is a margin of error! Is there usually on similar questions??
Original post by Positivedani
I put that and emailed my teacher and he said that its fine and the mark scheme will offer a range of answers xx


that's reassuring, thank you :smile: xx
Can somebody please post a C3 mark scheme? That test was so dodgy!
Original post by 123456789s
That's what I thought at first but I checked with my teacher after the exam and said it was correct as they are measuring the temperature increase and if the reaction carried on the end temp woulove been 18 making the answer 0 so it didn't make sence.


Original post by TrixieOwl
I used 29cm3. And got 2436J I hope there is a margin of error! Is there usually on similar questions??


but the volume was still 55? not 30 (or 29)

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