2016 AQA GCSE Chemistry Unofficial mark scheme 2016

Could you do a foundation mark scheme please? thanks

Question 1
Electron shell: 2,3( 1 mark)
Nucleus( 1 mark)
Neutron is uncharged, proton has a charge of +1 ( 3 marks)

Not in form 2,8,8, has 1,8. Neon has 10 electrons, the structure had 9 electrons, doesn't have a full outer shell but neon does (
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. The ethanol produced from crude oil is more pure than plants and biofuel.Crude oil is more widely available, crude oil is more reliable.

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

I reckon i've got 54-55 with harsh marking. By the way 20.3 is a wrong answer! You are meant to place it in 2 decimal figures (from the graph) for 2 marks. So in reality the answer is 20.30 not 20.3. How do I know this? 1) It was a 2 marker. 2) Our teacher is an AQA part time examiner and that is what he told us.

Was the two conditions for cracking: high temperature and hot catalyst


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For the ethene and steam advantage, could you produce it produces pure ethanol where as fermentation doesn't which means less is required? Also can you say put a lid on the beaker? Finally, could I get away with saying l saturated oil rather than saturated fat for the final question?

Most definitely and I think so

For which questions and thank you for the fast reply

Omdsss I think I did good looking at this but thank you so much this is really amazing!

Damnit I think I only got about 40!!! I need 50 in all units to get an A* overall (due to my crap ISA grade)

I got an A in my ISA like 90 UMS How much A's/ A*'s do i need in the exam(s) for an A* overall ?? thnx

what's ur isa mark?

what's ur isa mark?

The First question is just protons +1 and neutrons 0

That's the catalyst, yes, but I think you just needed to mention the presence of an aluminium oxide catalyst.

I reckon i've got 54-55 with harsh marking. By the way 20.3 is a wrong answer! You are meant to place it in 2 decimal figures (from the graph) for 2 marks. So in reality the answer is 20.30 not 20.3. How do I know this? 1) It was a 2 marker. 2) Our teacher is an AQA part time examiner and that is what he told us.