2016 AQA GCSE Chemistry Unofficial mark scheme 2016

For the question about how to reduce heat loss, I put add a lid so that less heat is lost to the surroundings. Is that right??

From this mark scheme, I got 52 i think. Is that likely to be an A*?

Also, on the Coursework, I got 40/50. If I get A* on each of C1,2 and 3, how likely am I to get an A* overall?

Thanks

WOW! Those are great marks! I mentioned the same thing right at the end just for arguments sake after actually providing the correct answer, but I don't think it will be mark-worthy because it does not necessarily answer the question. I may be wrong though!

I did say that but I'm not sure if it's a mark

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, 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 don't see why that wouldn't be right

Given the premise that "most of the people who use TSR are in the % of students that get >B grades " and that most of the people here today are saying how well they've done in this test, I'd say we can conclude that a high amount of people posting here now will get very good grades. This is because they will have something like 45+ marks so the average here today would be around 45-50 marks = A*. The boundaries are going to be very very high if this is the case nationwide.

What heat loss question???

The one about what changes could you make to the apparatus to get a better reflection of the energy content of each fuel, something along those lines.

I don't think steel is corrosion resistant

Was that definitely question 5?

I don't think steel is corrosion resistant

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


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