AQA Chemistry Paper 2 AS Level 2016 Unofficial Mark Scheme

^ And so the invasion of people using the unofficial mark scheme to cheat on their mock tests begins

I just contacted TSR to ask what would be the thing to do.

Here paper 1 http://www.thestudentroom.co.uk/showthread.php?t=4125207

Sorry I do Edexcel physics and ocr biology, so I don't have the unofficial Mark scheme

I do Edexcel Physics and Bio as well so is there any chance you have those?

Sorry I didnt make one for physics, as there's not many people who wanted it. And I really wanted to forget about that physics test

Posted from TSR Mobile

Anymore answers are welcome and feel free to correct any mistakes. Thank you!

1.1 Kc=[product]/[Reactant 1][Reactant 2]
Unit- mol^-1dm^3

1.2 10.5 mol^-1dm^3

-Z-isomer (ignore my awful drawing, I tried doing it on my macbook)


-Equation for Cl free radical and ozone layer
Cl.+ O3 ---> ClO.+ O2
ClO.+ O3 ----> 2O2 + Cl.
-Drawing chloropentafluroethane

-Why those the molecule (one without Cl) not contribute to ozone depletion? Because doesn't have a C--Cl bond so no chlorine free radical is made.
-Why does greenhouse gases like Co2 absorb a lot IR? They have bonds that have high bond enthalpy or another answer I've seen is that it's because the bonds are polar

-Fluorine free radical and CH3CF2 (Check the formula I think it was that?)
Propagation Step 1: .F + CH3CF2 ----> .CH2CF2 + HF
Propagation Step 2: .CH2CF2 + F2 ---> CH2CF3 + .F

-Number of molecules + Avogadro constant question? 1.01 x 10^25

-Isooctane? Nomenclature- 2,2,4-trimethypentane
-Name how to separate Isooctane and octane and how?
Distillation and you heat the conical flask with temperature above 99 degrees so Isooctane compound vaporises but the other compound remains liquid. Condense in a cooling jacket.

-Oleic acid testing for unsaturated
Bromine water and Observation from orange to colourless

-Enthalpy change of Combustion of methanol- -307 kJmol^-1
-Why enthalpy change lower- neglecting the specific heat capacity of the calorimeter
-Uncertainty- 0.5/38*100= 1.32%
-Why Uncertainty of 0.5 is okay?
-Heat change for ethanol 11760 KJ maybe 11800KJ as it's in 3sf (I have a blurry memory about this one)

-Write the complete combustion of octane?
C8H18 + 12.5O2 -> 8CO2 + 9H2O
-Catalyst how it works
Lowers activation energy by providing an alternate route to a reaction
-How does NO and CO react?
2NO + 2CO ----> N2 + 2CO2
-Thin layer catalyst maybe because it's more cost effective and catalyst doesn't get used up during reaction so you don't need thick layer.

-Why are the two compound impossible to distinguish in precise mass spec?
Both has the same number of atoms for each element so same precise molecular mass.
-Infrared Radiation: O-H bond and 3230-3550 cm^-1

6 Marker: Alcohol (hydrogen bonds, permanent dipole dipole, van der waals) Aldehyde (permanent dipole dipole and van der waals) and alkane (van der waals)

7 Marker electrophilic addition
Outline Mechanism: arrow from double bond to H(delta plus) arrow from bond H---Br to Br)
Tertiary Carbonation ion is more stable than secondary carbocation because alkyl groups is electron releasing and stabilises the carbocation. So most stable carbocation is formed more. 3bromo is more stable than 2bromo.

-Excess find moles of both and magnesium has more moles than the other compound so more magnesium is needed for a the first compound to react.
-Graph- I drew it lower and slower because there's fewer moles of reactants. Should be lower and quicker according to other because the concentration increased.

-Acidified potassium dichromate display formula both ketone and carboxylic acid and equation

CH3CH(OH)CH2OH + 3[O] → CH3COCOOH + 2H2O

-Reflux Apparatus


- Suggests how Anti Bumping Granules works? Found this online
It is also known as Boiling chip. They are small, insoluble, porous stones made of calcium carbonate or silicon carbide. These stones have pores inside which provide cavities both to trap air and to provide spaces where bubbles of solvent vapor can form. When a boiling chip is heated in a solvent, it releases tiny bubbles. These bubbles ensure even boiling and prevent bumping and boiling over and loss of the solution.*
-What is the structure when not in excess?
Aldehyde and ketone one

Multiple Choices
-orange to red, aldehyde one with cho-
-Increase Temp- makes KC increase and yield increase C
-Last question multiple choice is C
-The C,H,O is B- ethanoic acid
-Nucleophilic Substitution
-Total Equilibrium moles 18 of
A+3B->C+2D
-The Cyclohexene general formula- CnH2n-2
-Cracking equation A
-Percentage yield is 86.6%
-Polymer question Which is the alkene- D
-Maxwell Graph- C That number of molecules with E>Eais to the right of the line
-Mechanism Pic B
-Sulphur dioxide removed in gas station with CaO
-1064 missing enthalpy B


For the first 10 questions these may be the answers credit to @quiin f : CDDBAADCAB
Answers to 15 MCQ in order but maybe wrong credit to @britishtf2 :
CDDABBDCABCDCBC

the cyclo hexane general formula you write is wronge it is CnH2n it is the same as a alkene

X

https://www.scribd.com/doc/315582861/Chemistry-Unit-2-AQA-Notes
https://www.scribd.com/doc/299729097/UNIT-4-DEFINITIONS-docx
https://www.scribd.com/doc/299729094/CHEM4-docx
https://www.scribd.com/doc/299729076/Chemistry-Unit-5-definitions-docx
https://www.scribd.com/doc/299729073/Chemistry-Unit-5-docx
https://www.scribd.com/doc/290702428/CHEMISTRY-AQA-UNIT-1-NOTES
Please feel free to share these notes. If you can't access them, email me: [email protected]

These are really good! Thank you

Sorry I didnt make one for physics, as there's not many people who wanted it. And I really wanted to forget about that physics test

Posted from TSR Mobile

Anymore answers are welcome and feel free to correct any mistakes. Thank you!

1.1 Kc=[product]/[Reactant 1][Reactant 2]
Unit- mol^-1dm^3

1.2 10.5 mol^-1dm^3

-Z-isomer (ignore my awful drawing, I tried doing it on my macbook)


-Equation for Cl free radical and ozone layer
Cl.+ O3 ---> ClO.+ O2
ClO.+ O3 ----> 2O2 + Cl.
-Drawing chloropentafluroethane

-Why those the molecule (one without Cl) not contribute to ozone depletion? Because doesn't have a C--Cl bond so no chlorine free radical is made.
-Why does greenhouse gases like Co2 absorb a lot IR? They have bonds that have high bond enthalpy or another answer I've seen is that it's because the bonds are polar

-Fluorine free radical and CH3CF2 (Check the formula I think it was that?)
Propagation Step 1: .F + CH3CF2 ----> .CH2CF2 + HF
Propagation Step 2: .CH2CF2 + F2 ---> CH2CF3 + .F

-Number of molecules + Avogadro constant question? 1.01 x 10^25

-Isooctane? Nomenclature- 2,2,4-trimethypentane
-Name how to separate Isooctane and octane and how?
Distillation and you heat the conical flask with temperature above 99 degrees so Isooctane compound vaporises but the other compound remains liquid. Condense in a cooling jacket.

-Oleic acid testing for unsaturated
Bromine water and Observation from orange to colourless

-Enthalpy change of Combustion of methanol- -307 kJmol^-1
-Why enthalpy change lower- neglecting the specific heat capacity of the calorimeter
-Uncertainty- 0.5/38*100= 1.32%
-Why Uncertainty of 0.5 is okay?
-Heat change for ethanol 11760 KJ maybe 11800KJ as it's in 3sf (I have a blurry memory about this one)

-Write the complete combustion of octane?
C8H18 + 12.5O2 -> 8CO2 + 9H2O
-Catalyst how it works
Lowers activation energy by providing an alternate route to a reaction
-How does NO and CO react?
2NO + 2CO ----> N2 + 2CO2
-Thin layer catalyst maybe because it's more cost effective and catalyst doesn't get used up during reaction so you don't need thick layer.

-Why are the two compound impossible to distinguish in precise mass spec?
Both has the same number of atoms for each element so same precise molecular mass.
-Infrared Radiation: O-H bond and 3230-3550 cm^-1

6 Marker: Alcohol (hydrogen bonds, permanent dipole dipole, van der waals) Aldehyde (permanent dipole dipole and van der waals) and alkane (van der waals)

7 Marker electrophilic addition
Outline Mechanism: arrow from double bond to H(delta plus) arrow from bond H---Br to Br)
Tertiary Carbonation ion is more stable than secondary carbocation because alkyl groups is electron releasing and stabilises the carbocation. So most stable carbocation is formed more. 3bromo is more stable than 2bromo.

-Excess find moles of both and magnesium has more moles than the other compound so more magnesium is needed for a the first compound to react.
-Graph- I drew it lower and slower because there's fewer moles of reactants. Should be lower and quicker according to other because the concentration increased.

-Acidified potassium dichromate display formula both ketone and carboxylic acid and equation

CH3CH(OH)CH2OH + 3[O] → CH3COCOOH + 2H2O

-Reflux Apparatus


- Suggests how Anti Bumping Granules works? Found this online
It is also known as Boiling chip. They are small, insoluble, porous stones made of calcium carbonate or silicon carbide. These stones have pores inside which provide cavities both to trap air and to provide spaces where bubbles of solvent vapor can form. When a boiling chip is heated in a solvent, it releases tiny bubbles. These bubbles ensure even boiling and prevent bumping and boiling over and loss of the solution.*
-What is the structure when not in excess?
Aldehyde and ketone one

Multiple Choices
-orange to red, aldehyde one with cho-
-Increase Temp- makes KC increase and yield increase C
-Last question multiple choice is C
-The C,H,O is B- ethanoic acid
-Nucleophilic Substitution
-Total Equilibrium moles 18 of
A+3B->C+2D
-The Cyclohexene general formula- CnH2n-2
-Cracking equation A
-Percentage yield is 86.6%
-Polymer question Which is the alkene- D
-Maxwell Graph- C That number of molecules with E>Eais to the right of the line
-Mechanism Pic B
-Sulphur dioxide removed in gas station with CaO
-1064 missing enthalpy B


For the first 10 questions these may be the answers credit to @quiin f : CDDBAADCAB
Answers to 15 MCQ in order but maybe wrong credit to @britishtf2 :
CDDABBDCABCDCBC