2016 AQA GCSE Chemistry Unofficial mark scheme 2016

yep! but this unofficial thing saying 4Fe at the start it isn't

Question 2c could also be:
Add insulation to the beaker so less heat is lost meaning the final temperature of the water is more accurate.

No check yourself, he wrote 2Fe2O3

For the balancing equation question (2 marks) I put:

2Fe2O3 + 3CO --> 2Fe2 + 3CO2

I know this is wrong because it's supposed to be 4Fe , but how many marks do you think this would lose?

Apart from that I think it was definitely a much easier paper than previous years! So I'm guessing the a* grade boundary is around 51/60

was the reactivity not todo with pottasium is at the top so requires more energy to decompose where as copper is closer to the bottom and had a difference of 3.1g

I think I got 24,what grade would that be

for the distillation question would it have been okay to say
-vaporise gases
-pass through fractional column that is cooler at the top and hotter at the bottom
-condenses at different temperature so can be tapped off separately

if you said that for the 6 mark, that wouldn't get you many marks because that is not what the question asked? what question was this?

this was the 3 mark on distillation of ethanol and water, towards the end

Question 1
Electron shell: 2,3( 1 mark)
nucleus( 1 mark)
( +1), electrons( -1), neutron is uncharged( 3 marks)

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, 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)

58 marks I think

From this mark scheme i got roughly 47, what grade is that likely to be?

A but A* if AQA feel generous and lower the grade boundaries