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2016 AQA GCSE Chemistry Unofficial mark scheme 2016

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Original post by Bantalicoius
Any idea about grade boundaries?
my thoughts were;
52-60 A*
45-51 A
35-44 B
24-34 C

Only guessing from last years grade boundaries and how easy i found that one compared to today's exam.


52-60 whatttt? I say between 50-52 because last year was easier
Original post by redsoules
Bit late now darling.

It was asking about the Boron element and its placement of electrons. You basically had to just add 3 (x's or O's) to the outer shells. (Maybe just 2 can't remember) but basically boron has 5 electrons so I think it gave you 2 electrons to start and just add 3 more. (or 2 more)


If went through all my paper at the end and made sure I hadn't missed any so I'm really confused
Original post by sunny181113
52-60 whatttt? I say between 50-52 because last year was easier


Ridiculous boundaries.

52-60 A* Which means a total of 8 marks maximum to be lost. Thats literally about 2-3 questions. Almost a perfect paper.

I doubt AQA will hold such high standards as that, the average papers that come in that are almost perfect will not exceed a certain amount. So if only 50/10000 get 52-60 they wouldn't class that as an A* because its too small a group. It would need a much larger amount like something a long the lines of 200-300/10000 who lost a maximum of 8 marks. That is unlikely really.
SAME
Original post by abigail_lions
If went through all my paper at the end and made sure I hadn't missed any so I'm really confused


After doing the first few questions, other than this one, I realised I forgot to do this question, and quickly did it. There weren't any lines for writing, it just told you to draw on the diagram, so it was quite easy to miss, given the stress.:s-smilie:
You're probably not the only one though.:smile:
For question 3, instead of thermal decomposition could you get a mark for displacement? :s-smilie:
I missed the first question somehow and many others did too... HOW?!?!
[QUOTE="Daniaaburass;64953349"]
Original post by Daniaaburass
Are steam and catalyst right for cracking?

And I wrote carbon monoxide because of incomplete combustion
For the neon one I didn't compare what the diagram showed.
Are these right??!


Carbon monoxide would be incorrect as it is a gas, and therefore not visible on the bottom of the beaker. However if you have referred to incomplete/partial combustion in your explanation then you will probably get a mark.
Original post by ScienceFantatic
Question 1
Electron shell: 2,3( 1 mark)
nucleus( 1 mark)
( +1), electrons( -1), neutron is uncharged( 3 marks)- not sure if it was in the nucleus or just the atom overall

Not in form 2,8,8, has 1,8Boron has 10 electrons, the structure had 9 electrons( 3 marks)

Question 2
Tick box: copper oxide(1)

20.3(2 marks)

Digital thermometer, more precise and not subject to human error
Beaker insulated(2)

Carbon particles produced( particulates)Insufficient oxygen or incomplete combustion(2)

Best fuel because it produces least smoke/ burns the most cleanly. Produces the most energy per g(2)

Question 3
Advantages of hydrogen;
Only product water
Renewable
Provides more energy
No co2 or s02 released

Disadvantages:
Hydrogen is explosive
Hard to store because it is a gas
From natural gas( methane which is a greenhouse gas)
Engines need to be converted( 6 marks)

Thermal decomposition(1)

Question on potassium carbonate: doesn't fully thermally decompose, co2 not released, Bunsen burner temperature is not high enough( 3 marks)

Reactivity question: the lower the metal on the reactivity series, the easier it is broken down(2)

Question 4:
Conditions for cracking: high temperatures and a hot catalyst(2)

Fermentation question: sugar is dissolved and yeast is added to make ethanol(2)


Ethanol question: ethene is reacted with steam at high temperatures and catalyst(2)

Advantages and disadvantages of crude oil vs plants: Crude oil is a continuous process so faster, crude oil is more widely available, crude oil more reliable and things are set up for crude oil fractions

Non renewable, co2( global warming), SO2

(4 marks)

Question 5
metal ores are ores which contain enough of the metal to be worthwhile extracting( 1 mark)

It is converted to steel because cast iron is brittle or to make it stronger
Steel has more uses
Corrosion resistant
( 2 marks)

2Fe2O3+ 3C = 4Fe+ 3CO2( 2 marks)

It is not sent to landfill because this takes up space and causes pollution
It is not reused as it might have lost its strength and become unstable. Saves energy being used. Conserves raw materials
3 marks)

Question on distillation: Heat mixture between 80-99 degrees, the ethanol evaporates, cools and condenses to form pure ethanol and then raise temperature to 100 when all ethanol has evaporated to do the same to water( 3 marks).

Question on carbon neutral: carbon dioxide is a greenhouse gas
This takes up CO2 when it grows in photosynthesis
The same amount is released when biofuel or oils are burned
So no overall increase in CO2
Continuous Carbon Cycle(3)

Last question on hydrogenation; 60 degrees, reacted with hydrogen, nickel catalyst, double bonds converted into single bonds, increasing boiling point, done so that's it's a solid at room temperature for a thick, spreadable consistency (5)

Mark somewhere for completing drawing of the alkane(1)

Bromine goes colourless somewhere(1)

Took me a while to make so any rep would be much appreciated :smile:


Last question melting point is increased rather than boiling point and the one before it is heated at 79 and then condensed no need to evapourate water
For the final part of Q1 it asked about neon, not boron, don't know if that's been said
Original post by Rangzii
For the final part of Q1 it asked about neon, not boron, don't know if that's been said


I remember the Neon part. Completely forgot what was the question/task was though? Was it diagram? Or what?
Original post by ScienceFantatic
Question 1
Electron shell: 2,3( 1 mark)
nucleus( 1 mark)
( +1), electrons( -1), neutron is uncharged( 3 marks)- not sure if it was in the nucleus or just the atom overall

Not in form 2,8,8, has 1,8Boron has 10 electrons, the structure had 9 electrons( 3 marks)

Question 2
Tick box: copper oxide(1)

20.3(2 marks)

Digital thermometer, more precise and not subject to human error
Beaker insulated(2)

Carbon particles produced( particulates)Insufficient oxygen or incomplete combustion(2)

Best fuel because it produces least smoke/ burns the most cleanly. Produces the most energy per g(2)

Question 3
Advantages of hydrogen;
Only product water
Renewable
Provides more energy
No co2 or s02 released

Disadvantages:
Hydrogen is explosive
Hard to store because it is a gas
From natural gas( methane which is a greenhouse gas)
Engines need to be converted( 6 marks)

Thermal decomposition(1)

Question on potassium carbonate: doesn't fully thermally decompose, co2 not released, Bunsen burner temperature is not high enough( 3 marks)

Reactivity question: the lower the metal on the reactivity series, the easier it is broken down(2)

Question 4:
Conditions for cracking: high temperatures and a hot catalyst(2)

Fermentation question: sugar is dissolved and yeast is added to make ethanol(2)


Ethanol question: ethene is reacted with steam at high temperatures and catalyst(2)

Advantages and disadvantages of crude oil vs plants: Crude oil is a continuous process so faster, crude oil is more widely available, crude oil more reliable and things are set up for crude oil fractions

Non renewable, co2( global warming), SO2

(4 marks)

Question 5
metal ores are ores which contain enough of the metal to be worthwhile extracting( 1 mark)

It is converted to steel because cast iron is brittle or to make it stronger
Steel has more uses
Corrosion resistant
( 2 marks)

2Fe2O3+ 3C = 4Fe+ 3CO2( 2 marks)

It is not sent to landfill because this takes up space and causes pollution
It is not reused as it might have lost its strength and become unstable. Saves energy being used. Conserves raw materials
3 marks)

Question on distillation: Heat mixture between 80-99 degrees, the ethanol evaporates, cools and condenses to form pure ethanol and then raise temperature to 100 when all ethanol has evaporated to do the same to water( 3 marks).

Question on carbon neutral: carbon dioxide is a greenhouse gas
This takes up CO2 when it grows in photosynthesis
The same amount is released when biofuel or oils are burned
So no overall increase in CO2
Continuous Carbon Cycle(3)

Last question on hydrogenation; 60 degrees, reacted with hydrogen, nickel catalyst, double bonds converted into single bonds, increasing boiling point, done so that's it's a solid at room temperature for a thick, spreadable consistency (5)

Mark somewhere for completing drawing of the alkane(1)

Bromine goes colourless somewhere(1)

Took me a while to make so any rep would be much appreciated :smile:

LEGEND
Reply 232
think i got around 55 so so happy
Original post by redsoules
I remember the Neon part. Completely forgot what was the question/task was though? Was it diagram? Or what?


It was the one about not in the form 2,8,8 etc.
I feel like I got about 45, compared to the 51 I got on the mock which was last year's paper. I understand C2 and C3 much better though, so that might just boost my grade after full marks on my ISAs!
"Question 1
Electron shell: 2,3( 1 mark)
nucleus( 1 mark)
( +1), electrons( -1), neutron is uncharged( 3 marks)- not sure if it was in the nucleus or just the atom overall

Not in form 2,8,8, has 1,8Boron has 10 electrons, the structure had 9 electrons( 3 marks)"

This part "Not in form 2,8,8, has 1,8Boron has 10 electrons, the structure had 9 electrons( 3 marks)""

Can't make out what it's meant to mean? Boron has 5 electrons. Neon has 10 electrons and I can't remember the question for Neon.
Reply 236
Original post by redsoules
I remember the Neon part. Completely forgot what was the question/task was though? Was it diagram? Or what?

It showed a diagram of neon but it was drawn with 8 electrons on the inner shell and 1 on the outer so you had to say what was wrong with the diagram-should be 2,8 as neon is a noble gas, should have 10 electrons not 9 etc
Original post by Rangzii
It was the one about not in the form 2,8,8 etc.


Ah.. the diagram showed a Neon atom (incorrectly) with something like 9 electrons in the inner shell. You had to explain? why this was wrong? Or describe something?

Basically, it was the electronic configuration. But I can't remember exactly what the question asked so I can't even think of the answer.
It was 8 on the inner and 1 on the outer shell, had to explain what was wrong

Original post by redsoules
Ah.. the diagram showed a Neon atom (incorrectly) with something like 9 electrons in the inner shell. You had to explain? why this was wrong? Or describe something?

Basically, it was the electronic configuration. But I can't remember exactly what the question asked so I can't even think of the answer.
Original post by ScienceFantatic
Question 1
Electron shell: 2,3( 1 mark)
nucleus( 1 mark)
( +1), electrons( -1), neutron is uncharged( 3 marks)- not sure if it was in the nucleus or just the atom overall

Not in form 2,8,8, has 1,8Boron has 10 electrons, the structure had 9 electrons( 3 marks)

Question 2
Tick box: copper oxide(1)

20.3(2 marks)

Digital thermometer, more precise and not subject to human error
Beaker insulated(2)

Carbon particles produced( particulates)Insufficient oxygen or incomplete combustion(2)

Best fuel because it produces least smoke/ burns the most cleanly. Produces the most energy per g(2)

Question 3
Advantages of hydrogen;
Only product water
Renewable
Provides more energy
No co2 or s02 released

Disadvantages:
Hydrogen is explosive
Hard to store because it is a gas
From natural gas( methane which is a greenhouse gas)
Engines need to be converted( 6 marks)

Thermal decomposition(1)

Question on potassium carbonate: doesn't fully thermally decompose, co2 not released, Bunsen burner temperature is not high enough( 3 marks)

Reactivity question: the lower the metal on the reactivity series, the easier it is broken down(2)

Question 4:
Conditions for cracking: high temperatures and a hot catalyst(2)

Fermentation question: sugar is dissolved and yeast is added to make ethanol(2)


Ethanol question: ethene is reacted with steam at high temperatures and catalyst(2)

Advantages and disadvantages of crude oil vs plants: Crude oil is a continuous process so faster, crude oil is more widely available, crude oil more reliable and things are set up for crude oil fractions

Non renewable, co2( global warming), SO2

(4 marks)

Question 5
metal ores are ores which contain enough of the metal to be worthwhile extracting( 1 mark)

It is converted to steel because cast iron is brittle or to make it stronger
Steel has more uses
Corrosion resistant
( 2 marks)

2Fe2O3+ 3C = 4Fe+ 3CO2( 2 marks)

It is not sent to landfill because this takes up space and causes pollution
It is not reused as it might have lost its strength and become unstable. Saves energy being used. Conserves raw materials
3 marks)

Question on distillation: Heat mixture between 80-99 degrees, the ethanol evaporates, cools and condenses to form pure ethanol and then raise temperature to 100 when all ethanol has evaporated to do the same to water( 3 marks).

Question on carbon neutral: carbon dioxide is a greenhouse gas
This takes up CO2 when it grows in photosynthesis
The same amount is released when biofuel or oils are burned
So no overall increase in CO2
Continuous Carbon Cycle(3)

Last question on hydrogenation; 60 degrees, reacted with hydrogen, nickel catalyst, double bonds converted into single bonds, increasing boiling point, done so that's it's a solid at room temperature for a thick, spreadable consistency (5)

Mark somewhere for completing drawing of the alkane(1)

Bromine goes colourless somewhere(1)

Took me a while to make so any rep would be much appreciated :smile:


thanks victor!!

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