i wrote add a lid to prevent heat from escaping and then crossed it out and wrote keeping the hydrocarbons in for more than 2 minutes for clear results. ugsdshhdh man i hate it when this happens
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2016 AQA GCSE Chemistry Unofficial mark scheme 2016 watch
- 20-05-2016 10:31
(Original post by ScienceFantatic)
- 20-05-2016 12:37
This is for the higher tier
Question 1Spoiler:Question 2ShowElectron 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)Spoiler:Question 3ShowTick box: copper oxide(1)
Digital thermometer, more precise and not subject to human error
Beaker insulated( any forms of insulation really:lid, wool etc.(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)
Spoiler:Question 4:ShowAdvantages of hydrogen;
Only product water
Provides more energy
No co2 or s02 released
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)
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)Spoiler:Question 5ShowConditions for cracking: high temperatures/400-700 degrees and a (hot) catalyst/Aluminium Oxide (2 marks)
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)Spoiler:Random ones:Showmetal 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
( 2 marks)
2Fe2O3+ 3C = 4Fe+ 3CO2( 2 marks) 1 mark for correctly balaned, another for realising Iron was made.
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. It is recycled because it saves energy being used. Conserves raw material. Less Quarrying needed.
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. Maybe a mark for saying ethanol has a lower boiling point than 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 melting point, done so that's it's a solid at room temperature for a thick, spreadable consistency (5)Spoiler:Took me a while to make so any rep would be much appreciated . I hope this helped you all, I was getting impatient with it not being made in time so I made my own.ShowMark somewhere for completing drawing of the alkane(1)
Bromine goes colourless somewhere(1) Clear is not acceptable.
And also will i lose a mark if i correctly balanced the equation but accidently wrote Fe4, not 4Fe?
- 20-05-2016 12:58
- 20-05-2016 13:04
I wrote use foil to prevent heat loss for the apparatus question would that be sufficient
- 20-05-2016 16:48
anyone for the distillation question?
- 20-05-2016 16:52
0 estimated marks so far😔
- 20-05-2016 16:55
- 20-05-2016 17:41
(Original post by Social Elitist)
- 20-05-2016 17:44
This is painful to read... I felt so good when I just finished the exam - thinking I'd get B-A... but some reading errors that slipped by and gaps of knowledge might just get me a B at most.
Pray to God that there are anmolous marks and that I would get something higher than a C. Asian parents don't find C's acceptable, so I would feel too ashamed for myself, even after more than 12 hours C1 revision were gone the gutter...
- 20-05-2016 18:05
(Original post by redsoules)
- 20-05-2016 18:06
This is funny. I'm in the same situation. Revised for hours. Only to get 2 hours sleep before the exam and then mis-read or make silly mistakes that cost me bigtime. What a shame, hopefully I'll get a good enough grade to take A levels next year though - Which are worth much more than standard GCSE's
- 20-05-2016 18:11
- 20-05-2016 18:50
For the ethene question could you say
Ethanol more concentrate
So less energy and money needed to purify it
- 20-05-2016 19:15
Your ****ed mate
- 20-05-2016 19:48
Guys, you could also write that crude oil is cheaper in comparison to plant oils and explain it of course if anyone wanted to know
- 20-05-2016 19:56
Also to everyone worrying (including myself) remember , this is an UNOFFICIAL markscheme, there will be soooo many more things on the actual one , sooooo many more "allows" so don't worry!! Even still, contrary to a lot of people here a lot of the country did find it reasonably difficult so the grade boundaries won't be all that high. The max would be 51 tops ALSO you have C2 and C3 , honest to God if you do solid revision and know your **** inside out and do all the past papers, there will literally be no reason for you not to get even 100% in the next two papers and boost your grade, WE'RE ALL CAPABLE
Have a great day!
- 20-05-2016 19:56
You can also write in disadvantages of hydrogen that it is harder to distribute than petrol which can be distributed through petrol stations etc.
- 20-05-2016 22:11
- 20-05-2016 22:17
- 20-05-2016 22:18