Arithmeticae's Unofficial AQA C1 Mark Scheme Watch

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Hey there guys. This is my attempt at creating a (hopefully correct) bank of solution for the GCSE AQA C1 paper sat by a lot of us today.

Just a couple of things to clarify:

I don't do requests. Don't bother wasting your time.
No one's saying these are 100% correct, they're just what I've seen to be true and what I thought was right. If there's any problems you can spot, feel free to quote me in on them
These are by no means the only correct (assuming they are even correct ) answers. If you think there are alternative correct solutions, just quote me and I'll edit them in.

Now we've got all that out of the way, here we go!

P.S. If anyone starts a massive argument about a 1 mark question, I will track you down and slit your throat with a rusty spoon, srs. k?

The Answers


Question 1


1ai) 2,4

1aii) Hydrogen + Oxygen ==> Water

1b)

·Carbon dioxide - contributes to climate change through greenhouse effect and absorbtion/re radiation of infrared.
·Sulfur dioxide - contributes to acid rain as it can react with rainwater in order to form an acidic solution, which can have also detrimental effects on wildlife.



Question 2


2ai) Reacting something with water.

2aii) The solid waste yeast is filtered off, and the ethanol is obtained through distillation.

2b)

Biodiesel is a renewable resource as it is made from vegetable oils which can be obtained from plants. In addition to this, it is carbon neutral as the only CO2 released is that which has been taken in through photosynthesis. Furthermore, it does not produce sulfur dioxide when burnt so it does not cause acid rain. On the other hand, it uses up valuable land which could instead be used for the purpose of growing food, which could cause food prices to increase.

Petroleum diesel releases significantly more carbon dioxide (4x as much) than biodiesel, which means it has more of a contribution to climate change through the greenhouse effect and also twice as much particulates which can cause global dimming as they prevent the sunlight from reaching the Earth. Petroleum is also a finite resource - we have a limited supply and will not be able to produce more when it runs out. It also requires significantly more work and energy to mine and extract than biodiesel.

Overall, I think that biodiesel is better to use as it is generally better for the environment and we will not run out of it as more can be made.



Question 3


3ai) When unsaturated hydrocarbons are reacted with bromine water, the water changes from orange to colourless. Therefore, the more unsatured hydrocarbons are present, the greater the amount of drops required for the bromine water to change as there are more carbon-carbon double bonds to react with. This means that we can conclude that the oils that react with more drops are higher in unsaturated fats than the oils that require less.


3aii) Company A, Test 2 because it seems to be an anomalous result as it does not fit in with the general trend.

3aiii) Temperature

3b)

·Vegio has more unsaturated fats than Company C
·Vegio has less unsaturated fats than Company B
·Vegio is 'less healthy' than Company A as it has less unsaturated fats, so it does not live up to its claim



Question 4

4ai) Phytomining

4aii)

·Because there is only a low concentration of copper compounds, so it is not economically viable
·Because it is energy inefficient, which means a lot of money will be wasted.

4aiii) 2CuO + C ==> 2Cu + CO2

4bi)

·Because it is cheaper than copper.
·Because it is more reactive than copper.

4bii) The copper ions travel to the negative electrode, where they are reduced to form copper atoms which gather on the negative electrode.


Question 5

5a) Calcium carbonate undergoes a thermal decomposition reaction when heated strongly, and forms calcium oxide (CaO) along with carbon dioxide (CO2)

5b)

·The reaction did not progress fully, perhaps because the temperatures were not high enough or it was not long for long enough.ss
·Some of the products were lost to the surroundings such as carbon dioxide or left behind on the equipment.


Question 6

6ai) Because he could not explain what causes continental drift.

6aii)X is the crust and Y is the mantle (or whatever the correct order was). [not sure if this is required or not, but it can't hurt.]

The Earth is made up of tectonic plates in the lithosphere (crust and upper part of the mantle). It is possible for these plates to move slightly. Radioactive processes in the mantle release heat and cause convection currents in the mantle (seafloor spreading), which causes the tectonic plates to slowly move away from each other due to the motion of the currents.

6bi) It has the same melting and boiling point, so it would freeze instead of liquefying and should be removed before the mixture reaches -200oC

6bii) Neon

6biii) Argon, because it has a very similar boiling point to oxygen so it will be difficult to seperate the two gases.


Question 7

7ai) Alkenes and alkanes

7aii) If catalytic cracking is taking place, there should be high temperatures and a catalyst should be present.

7aiii) Because it would cause the hydrocarbons to combust.

7aiv) Fractional distillation.

7bi) Butene molecule (H2C=CHCH2CH3)

7bii) The double bond 'splits open' which allows more butene molecules to bond on to the first one, so it forms long chains of butene monomers.


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GoldGhost
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(Original post by Arithmeticae)
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Woah thanks! By the way for the first question could you have put 'hydroxide' instead or is that completely different?

Also when is said about hydration? I said hydration is reacting ethene with steam to form ethanol does that count or not?
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GoldGhost
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(Original post by Arithmeticae)
Sorry, but IMO hydration only refers to water
Sorry I mean't for the second question about hydration, not the first question - are we talking about the same question?

I think I might have confused myself haha
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badaman
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Wow thanks for this
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LollyPopzicle
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(Original post by Arithmeticae)
Sorry, but IMO hydration only refers to water
Lol Hydration is reacting ethene with steam
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LollyPopzicle
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(Original post by GoldGhost)
Sorry I mean't for the second question about hydration, not the first question - are we talking about the same question?

I think I might have confused myself haha
Don't worry mate, you're right he's only partially correct
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GoldGhost
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(Original post by Arithmeticae)
Steam is water vapour...

Google 'hydration reaction'
That's what I put, sorry for confusing you hehe I put ethene is reacted with steam to produce ethanol. I think there might be some confusion over what question I was asking you about
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Magistl
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(Original post by Arithmeticae)
Sorry, but IMO hydration only refers to water
Could I get a mark through saying: "Wegener couldn't explain it due to a lack of evidence?" please say yes, I scribbled out the correct answer otherwise XD
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LollyPopzicle
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(Original post by Arithmeticae)
Steam is water vapour...

Google 'hydration reaction'
I did and this came up
The hydration of ethene to make ethanol
A reminder of the facts
Ethene is mixed with steam and passed over a catalyst consisting of solid silicon dioxide coated with phosphoric(V) acid. The temperature used is 300°C and the pressure is about 60 to 70 atmospheres.
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Magistl
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(Original post by Arithmeticae)
probably, it sounds ok but aqa have be known to be very picky with their marking
If that's the case I may have to borrow your rusty spoon. *stares solemnly at the AQA website*
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aerohotchoc
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(Original post by Magistl)
Could I get a mark through saying: "Wegener couldn't explain it due to a lack of evidence?" please say yes, I scribbled out the correct answer otherwise XD
I think I've seen that answer in the mark scheme in a past paper of the same question, so should be okay
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GoldGhost
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(Original post by Arithmeticae)
Hey there guys. This is my attempt at creating a (hopefully correct) bank of solution for the GCSE AQA B1 paper sat by a lot of us today.

Just a couple of things to clarify:

I don't do requests. Don't bother wasting your time.
No one's saying these are 100% correct, they're just what I've seen to be true and what I thought was right. If there's any problems you can spot, feel free to quote me in on them
These are by no means the only correct (assuming they are even correct ) answers. If you think there are alternative correct solutions, just quote me and I'll edit them in.

Now we've got all that out of the way, here we go!

P.S. If anyone starts a massive argument about a 1 mark question, I will track you down and slit your throat with a rusty spoon, k?

The Answers


Question 1


1ai) 2,4

1 mark

1aii) Hydrogen + Oxygen ==> Water

1 mark

1b)

·Carbon dioxide - contributes to climate change through greenhouse effect and absorbtion/re radiation of infrared.
·Sulfur dioxide - contributes to acid rain as it can react with rainwater in order to form an acidic solution, which can have also detrimental effects on wildlife.

4 marks



Question 2


2ai) Reacting something with water.

1 mark

2aii) The solid waste yeast is filtered off, and the ethanol is obtained through distillation.

2 marks

2b)

Biodiesel is a renewable resource as it is made from vegetable oils which can be obtained from plants. In addition to this, it is carbon neutral as the only CO2 released is that which has been taken in through photosynthesis. Furthermore, it does not produce sulfur dioxide when burnt so it does not cause acid rain. On the other hand, it uses up valuable land which could instead be used for the purpose of growing food, which could cause food prices to increase.

Petroleum diesel releases significantly more carbon dioxide (4x as much) than biodiesel, which means it has more of a contribution to climate change through the greenhouse effect and also twice as much particulates which can cause global dimming as they prevent the sunlight from reaching the Earth. Petroleum is also a finite resource - we have a limited supply and will not be able to produce more when it runs out. It also requires significantly more work and energy to mine and extract than biodiesel.

Overall, I think that biodiesel is better to use as it is generally better for the environment and we will not run out of it as more can be made.

6 marks



Question 3


3ai) When unsaturated hydrocarbons are reacted with bromine water, the water changes from orange to colourless. Therefore, the more unsatured hydrocarbons are present, the greater the amount of drops required for the bromine water to change as there are more carbon-carbon double bonds to react with. This means that we can conclude that the oils that react with more drops are higher in unsaturated fats than the oils that require less.


3aii) Company A, Test 2 because it seems to be an anomalous result as it does not fit in with the general trend.

3aiii) Temperature

1 mark

3b)

·Vegio has more unsaturated fats than Company C
·Vegio has less unsaturated fats than Company B
·Vegio is 'less healthy' than Company A as it has less unsaturated fats, so it does not live up to its claim

3 marks



Question 4

4ai) Phytomining

1 mark

4aii)

·Because there is only a low concentration of copper compounds, so it is not economically viable
·Because it is energy inefficient, which means a lot of money will be wasted.

2 marks

4aiii) 2CuO + C ==> 2Cu + CO2

2 marks

4bi)

·Because it is cheaper than copper.
·Because it is more reactive than copper.

2 marks

4bii) The copper ions travel to the negative electrode, where they are reduced to form copper atoms which gather on the negative electrode.

2 marks



Question 5

5a) Calcium carbonate undergoes a thermal decomposition reaction when heated strongly, and forms calcium oxide (CaO) along with carbon dioxide (CO2)

3 marks

5b)

·The reaction did not progress fully, perhaps because the temperatures were not high enough or it was not long for long enough.ss
·Some of the products were lost to the surroundings such as carbon dioxide or left behind on the equipment.


Question 6

6ai) Because he could not explain what causes continental drift.

6aii)X is the crust and Y is the mantle (or whatever the correct order was). [not sure if this is required or not, but it can't hurt.]

The Earth is made up of tectonic plates in the lithosphere (crust and upper part of the mantle). It is possible for these plates to move slightly. Radioactive processes in the mantle release heat and cause convection currents in the mantle (seafloor spreading), which causes the tectonic plates to slowly move away from each other due to the motion of the currents.

5 marks

6bi) It has the same melting and boiling point, so it would freeze instead of liquefying and should be removed before the mixture reaches -200oC

1 mark

6bii) Neon

1 mark

6biii) Argon, because it has a very similar boiling point to oxygen so it will be difficult to seperate the two gases.

2 marks


Question 7

7ai) Alkenes and alkanes

1 mark

7aii) If catalytic cracking is taking place, there should be high temperatures and a catalyst should be present.

1 mark

7aiii) Because it would cause the hydrocarbons to combust.

1 mark

7aiv) Fractional distillation.

1 mark

7bi) Butene molecule (H2C=CHCH2CH3)

1 mark

7bii) The double bond 'splits open' which allows more butene molecules to bond on to the first one, so it forms long chains of butene monomers.

2 marks




I think these are marks available not too sure - if anyone can add a couple more in or adapt them, that would be good :-)
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LollyPopzicle
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(Original post by AlphaNick)
1) b) Should explicitly refer to global warming, not climate change

1) b) Rainwater is already acidic, you need to refer to it becoming more acidic than usual

2) b) You missed out a ton of points. Furthermore it wasn't a 'conclusion/evaluation' question - it was listing the advantages and disadvantages. Additionally you had to say the advantages and disadvantages of using biodiesel instead of petroleum - not the advantages / disadvantages of each as you've done.

3) a) i) This question was asking you to describe how they carried out the experiment, not to describe what happens with bromine water in the presence of unsaturated hydrocarbons. It should say that "bromine water was added in drops to a constant volume of different vegetable oils until they turned colourless from orange - this is recorded as the number of drops."

3) a) iii) Temperature is hardly an appropriate answer for this - they probably kept it at room temperature so you've lost a mark there. Answers should include things like interval size, amount of bromine water added per drop (ie volume), concentration perhaps.

3) b) Incorrect. It had the equal amount of unsaturated oils as one of them.

4) a) i) You completely forgot to mention the environmental implications of constructing a quarry in a low-grade ore site.

4) b) i) 'Cheaper' than copper isn't appropriate here. Instead you should say that copper reserves are depleting at a greater rate relative to iron.

4) b) ii) No mentions of reduced / gain of electrons? marks lost.

5) b) A glaring mistake here. He specifically said that he was measuring the mass of calcium oxide yield from the reaction - so mass lost as CO2 is irrelevant - marks lost here.

6) a) i) Not a very solid point but whatever.

6) b) i) 'Freeze' solidify is a better term here...

7) a) ii) This is weak. There should be a flame / the catalyst itself has to be hot.

7) b) ii) Needs to explicitly mention that the double bond breaks and forms a single bond, the remaining bond is used to join monomers of poly(butene).

I guess this exam didn't go so well for you.
Lol no you dont you need to say many butene molecules join up to form a long molecule
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GoldGhost
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[QUOTE=AlphaNick;48080200]Because climate change is vague - global dimming / warming are classed as climate change but carbon dioxide doesn't cause dimming.

No, you said it forms 'acid rain' - implying that rain is previously devoid of acidity.

I know, but still you answered the question incorrectly, it should be comparing advantages / disadvantages of using biodiesel instead of petroleum - not the advantages / disadvantages of either.

Close enough but you probably got one mark maximum.

Because do you really think that testing the experiment at 1 degree lower causes such an increased rate of reaction that it makes the unsaturated oils more effective at decolourising bromine water?

Yes, the named one had 16 drops, so did another one. So they were identical in unsaturated oils.

Yeah well it was a more solid answer by far.

Because the price of copper depends on the extraction method and reserves supplies.

So? Spec says that you're not meant to know about exothermic/endothermic reactions, but C1 June 2013 had a question "What type of reaction is this?" Answer was exothermic.

Nope - it was just the mass of calcium oxide produced - not the products as a whole, you had to ignore the production of CO2. Did you misread the question?[/QUOTE]


I think I might have misread the question for this question, what did you put?
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BBeyond
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For question 1b could you say carbon released when incomplete combustion occurs would cause global dimming?
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GoldGhost
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Did you have to specifically mention vergio in comparison to A and B? I just said that x has the least amount of unsaturated fats and x has the most?
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GoldGhost
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(Original post by AlphaNick)
As the spec says, flames from Bunsen burners are often not hot enough to cause full decomposition. Also I said that the reaction was incomplete.
I said that it may not have all thermally decomposed - is that partially correct?
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badaman
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(Original post by GoldGhost)
Did you have to specifically mention vergio in comparison to A and B? I just said that x has the least amount of unsaturated fats and x has the most?
Yeah.. I put like Vegio was healthier than ___ but less healthy than ___
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aerohotchoc
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(Original post by AlphaNick)
No, you said it forms 'acid rain' - implying that rain is previously devoid of acidity
The mark schemes are never that specific though- it will say
sulfur dioxide (1)
acid rain (1)
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GoldGhost
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(Original post by AlphaNick)
Yeah but it was 4 marks
Is that 1 or 2 marks then perhaps?
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