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2016 IGCSE Chemistry Paper 2 Unofficial Mark Scheme 2016

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How did Paper 2 IGCSE Chemistry go?

Edexcel iGCSE Chemistry Paper 2C 15 June, sorry should have specified in the question...
Please send the answers and the question numbers you remember :biggrin:
Please also point out any mistakes or mistakes in question numbers :biggrin:

1a) Glass rod / stirrer and Bunsen Burner
1b) Liquids that dissolve is solvent
1c) Colourless liquid is solution
1d) Solid insoluble impurities removed in stage 2 (filtration), salt crystals removed in stage 3 (crystallisation)
1d) Crystallisation point is when crystals begin to form
1e) Water evaporates from the heat

2a) Water levels rose as oxygen in air reduced as it reacted with iron to produce hydrated iron oxide, stopped as all oxygen had been used up
2b) Cant remember what it asked but it was:
iron? + sulphuric acid? -> iron sulphate + hydrogen
2c) 2HNO3 + CuO -> Cu(NO3)2 + H2O
2d) Warmed acid as it increased rate of reaction
2e) In excess when solid starts to form at the bottom (stops dissolving)

3a) Metal oxide is alkaline (e.g. sodium hydroxide) and non metal oxides are acidic (e.g. sulphur dioxide)
The question asked for the element that would form oxides, so any metal (sodium, magnesium etc.) is correct for the first one, and any non metal apart from argon is correct for the second one. you did not have to specify the oxide, i.e. magnesium oxide, sulphur dioxide etc.
3b) Dot cross diagram of MgCl with each with a full outer shell, and chloride ions with one donated electron, charges where Mg2+ and Cl- x2
3c) Ionic bonding is transfer of electrons, producing a positive and negative ion(s), with electro-static forces of attraction between oppositely charged ions
3d) Why ionic is strong: strong electro-static forces between oppositely charged ions which need a lot of energy to break

4a) Titration
4b) Pipette to add 25cm3
4c) Methyl orange is yellow before, orange OR red when neutral
4d) Fe2+ gives green precipitate, Fe3+ gives brown(/orange) precipitate
4e) Burrette readings, can't remember exact values but values had to be given to 2 decimal places
4f) 22.60, 22.45, 22.55 for the concordant results in boxes 2, 3, 4 with an average of 22.533....., 22.53 to have 2dp, like the given results


5a) Isomer has the same chemical formula but different structural formula
5b) Isomer of with 4 carbons and 8 hydrogens with a double bond
5c) Test with bromine water, which goes colourless in the one with a double bond (but-1-ene i think?) and stays orange in the other one
5d) CH3-CH2-CH2-OH
5e) Cant remember the monomer but ( )n with the double bond broken and carbon bonds outside brackets

6a) Refinery gas has lowest boiling point, bitumen was most viscous
6b) Long chain hydrocarbon -> C10H20 and x number of ethene I'm not sure about this one, this answer may not be correct, lots of people have put different things
6c) Cracking is important as shorter chain hydrocarbons are in higher demand, as they are used for cars (i.e. gasolene etc..)
6d) Long Hydrocarbon + Oxygen --> Carbon, Carbon Monoxide, Carbon Dioxide and Water
i think it is C8H18 + 6O2 > 6C + CO2 + CO + 9H2O, variants without Carbon may be accepted :smile:

7a) 2.75g
7b) Using 0.0625 moles from A, 1500 cm3 of Carbon Dioxide

cant remember question number but:

3:1 ratio electrons:Al so 20/3 moles of Al
mass= moles x mr so 6.666 x 27 = 180g






Hope this mark scheme helped!!! Good luck in Triple Physics and the rest of your exams!
(edited 7 years ago)

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Reply 1
Methyl orange
Before adding acid: yellow
When KOH neutralised: red

Liquid things dissolve in: C Solvent
Question after that: B Solution
Reply 2
Original post by Lelanor
Methyl orange
Before adding acid: yellow
When KOH neutralised: red

Liquid things dissolve in: C Solvent
Question after that: B Solution


do you remember what question number the methyl orange one was?
Reply 3
The second part of question one was bunsen burner...i can remember some of the other stuff but not the question numbers :P
Lol i am actually so dumb I put thermometer instead of glass rod/stirrer

the lesson i learnt from this is not to go into the exam dehydrated to the point where you get the most basic question wrong
Reply 5
Original post by rcmack
do you remember what question number the methyl orange one was?


No, sorry. But I've just remembered the answer to the first part of that question was titration.
Original post by Lelanor
Methyl orange
Before adding acid: yellow
When KOH neutralised: red

Liquid things dissolve in: C Solvent
Question after that: B Solution


Do you think they'll accept orange in place of red, the question wasn't that clear
If i just put Na for sodium would i get the mark?
Reply 8
Original post by Cheekymonkey2311
If i just put Na for sodium would i get the mark?


of course :smile:
How do you guys find it? :biggrin:
Reply 10
Original post by PrincessBO$$
How do you guys find it? :biggrin:


i feel it was alot easier than the past paper 2s
Reply 11
Original post by aaljhfgahsj
Do you think they'll accept orange in place of red, the question wasn't that clear



Yes I put orange too, it even says that the indicator turns orange when the solution is neutral in my textbook.
Reply 12
Firstly it's paper 2C not 1C
2.75 grams for the second last
1,500cm3 for the last question


Posted from TSR Mobile
Reply 13
Red is totally wrong,It is orange.Red is for acid.
(edited 7 years ago)
Reply 14
Orange at neutralisation not red. Red is acid.


Posted from TSR Mobile
Original post by rcmack
i feel it was alot easier than the past paper 2s


yep. Easier than last year. Worried about the grade boundaries :redface:
Reply 16
How does he know when the crystallisation point is reached? i wrote take a sample and let it cool in air and if it crystallises then the point has been reached.

And for the aluminium mass i got 180g.
Reply 17
Original post by Nurne
Orange at neutralisation not red. Red is acid.


Posted from TSR Mobile


thanks :smile:
Reply 19
Original post by Abodee1
How does he know when the crystallisation point is reached? i wrote take a sample and let it cool in air and if it crystallises then the point has been reached.

And for the aluminium mass i got 180g.


yea same, do you remember what question number that was?

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