[Picture~Perfect]

Hi all
As promised, here is a link to the paper, I've scanned it and uploaded to my skydive on hotmail. It may take a while to load, but you should be able to download and print it off as you wish
June 2012 paper
The mark scheme is in the next post, thanks to knocker

[Picture~Perfect]

Mark scheme
A big thanks to knocker for this mark scheme
If you use this please give them some rep.

Question 1:
(a) steeper line, ending twice as high (2)
(b) less steep line, ending 2/5 as high (2)
(c) steeper line, ending at same level (2)
(d) concentration of reactants decreases with time, hence frequency of collisions decreases as does the rate (2)
(e) 2 H2O2 --> 2 H2O + O2 (1)
(f) The HBr is not used up (1)

Question 2:
(a)(i) -49 (3)
(ii) it is an element (1)
(b) increases, 4 moles gas --> 2 moles gas, eqilibrium shifts right to oppose the change (3)
(c) increases, reaction is endothermic, equilibrium shifts right to oppose the change (3)
(d)(i) no net carbon produced (1)
(ii) CH3OH + 3/2 O2 --> CO2 + 2 H2O (1)
(iii) 3 H2 + 3/2 O2 --> 3 H2O (1)
(e) q = 4389 J, DH = - -399 kJ/mol (3)


Question 3:
(a) balancing equation 2/15/15/6(1)
(b) P4 = zero, H3PO4 = +5 (2)
(c) Add up Ar values to show they are different to 5dp (1)
(d)(i) speeds up rate of reaction without being used up (1)
(ii) addition of water (1)
(iii) CH3CH=CH2 + H2O --> CH3CH(OH)CH3, propan-2-ol (2)

Question 4:
(a) Forms brittle TiC (1)
(b)(i) 2 FeTiO3 + 7 Cl2 + 6 C --> 2 FeCl3 + 2 TiCl4 + 6 CO (1)
(ii) TiCl4 + FeCl3 + 7 Na --> Fe + Ti + 7 NaCl (1)
(c) Cu2+ + Fe --> Cu + Fe2+, Cu2+ ions reduced as they gain electrons (2)
(d) 2 O2- --> O2 + 4e (1)

Question 5:
(a)(i) Ba + 2 H2O --> Ba(OH)2 + H2 (1)
(ii) reactivity increases (1)
(b) Mg(OH)2 (1)
(c) Barium meal / X-ray tracer, insoluble (2)

Question 6:
(a)
(i) Cl2 --> 2 Cl.
CH2Cl2 + Cl. --> .CHCl2 + HCl
.CHCl2 + Cl2 --> CHCl3 + Cl. (3)
(ii) UV light, Free-radical substitution (2)
(b)
(i) CHCl3 + Cl2 --> CCl4 + HCl (1)
(ii) CHCl3 contains C-H bonds, no C-H absorption at 2850-3300 (2)
(c) CFC's - UV light breaks C-Cl bond, makes Cl. radicals
Cl. + O3 --> ClO. + O2
ClO. + O3 --> 2 O2 + Cl. chain reaction
2 O3 --> 3 O2 (4)
(d)
(i) CH2=C(F)CF3 (1)
(ii) it contains no C-Cl bonds (1)

Question 7:
(a)
(i) elimination mechanism (3)
(ii) E hex-3-ene (H's on opposite sides) and Z-hex-3-ene (H's on same side) (2)
(iii) Same MF and SF, different arrangement of atoms in space (2)
(b) H2SO4 electrophilic addition mechanism (4)

Question 8:
(a) Safety - NaOH is corrosive, Environmental - Process 2 uses CO2 from local factory, less CO2 emissions/global warming (2)
(b)
(i) Nucleophilic substitution with :OH- (3)
(ii) BCA (3)
(c) Fermentation, low temperature 35oC, High pressure, Yeast catalyst, aqueous solution, anaerobic conditions to prevent ethanol retaking with air to form ethanoic acid (4)
(d) primary alcohol, acidified potassium dichromate(VI)
CH2(OH)CH2CH2CH2OH + 4[O] --> HOOCCH2CH2COOH + 2 H2O (3)

Question 9:
(a)
(i) Iodine/I2, Cl2 + 2 I- --> 2 Cl- + I2, redox/displacement (3)
(ii) silver(I) chloride, Ag+ + Cl- --> AgCl, ppt dissolves (3)
(b)
(i) H+ + Cl- --> HCl, HCl (2)
(ii) 2 I- --> I2 + 2e-
H2SO4 + 8 H+ + 8 e- --> H2S + 4 H2O
H2SO4 = oxidising agent, yellow solid = sulfur/S/S8 (4)
(iii) NaOH reacts with H+, equilibrium shifts right to make more H+ and opppose the change
bromine is used in small quantities

The average of the last four papers is:
A: 74
B: 66
C: 57

[BlastOff]

Legend

Thanks for the effort, I'll be back in a bit to tot up my marks

[poopoo123]

thank you so much

[Mocking_bird]

Would rep you again if I could
Thanks a lot

[posting]

where is the ms again please?

[khalidpatel]

Thanks you sooo much!

[Casshern1456]

OMG I completely didn't see the question Q6,Q7 where you get 3 marks for drawing some curly arrows what have i done!!??

[berryripple]

(Original post by Casshern1456)
OMG I completely didn't see the question Q6,Q7 where you get 3 marks for drawing some curly arrows what have i done!!??

[TheGirlNextDoor]

(Original post by poopoo123)
thank you so much

Great username

(Original post by Mocking_bird)
Would rep you again if I could
Thanks a lot

You, my friend, know exactly what you're talking about when you mentioned Tom

[cuckoo99]

(Original post by Casshern1456)
OMG I completely didn't see the question Q6,Q7 where you get 3 marks for drawing some curly arrows what have i done!!??

holy **** FFS i didnt see that either OMG OMG OMG OMG EASY MARKS GONE :O:O:O:O

Edit: why have i been negged for this ?

[posting]

guys? i cant see the markscheme? If you guys can, how do i too?

[sandeep0767]

(Original post by Picture~Perfect)
Hi all
As promised, here is a link to the paper, I've scanned it and uploaded to my skydive on hotmail. It may take a while to load, but you should be able to download and print it off as you wish
June 2012 paper
I'll write my interpretation of the answers in the next post

i love you <3

[Casshern1456]

(Original post by cuckoo99)
holy **** FFS i didnt see that either OMG OMG OMG OMG EASY MARKS GONE :O:O:O:O

It is I dunno whether to think I'm stupid for missing out the easy mark or are they just daft for not making it clear and drawing out attention to the questions at the bottom ya know by actually putting lines in for us to WRITE ON.

[Picture~Perfect]

(Original post by Casshern1456)
OMG I completely didn't see the question Q6,Q7 where you get 3 marks for drawing some curly arrows what have i done!!??

It's only three marks, don't worry you can still do well

[knocker]

UNOFFICIAL MARK SCHEME - please point out any errors (done with paper in front of me and I'm a teacher...)

1(a) steeper line, ending twice as high (2)
(b) less steep line, ending 2/5 as high (2)
(c) steeper line, ending at same level (2)
(d) concentration of reactants decreases with time, hence frequency of collisions decreases as does the rate (2)
(e) 2 H2O2 --> 2 H2O + O2 (1)
(f) The HBr is not used up (1)

2(a)(i) -49 (3)
(ii) it is an element (1)
(b) increases, 4 moles gas --> 2 moles gas, eqilibrium shifts right to oppose the change (3)
(c) increases, reaction is endothermic, equilibrium shifts right to oppose the change (3)
(d)(i) no net carbon produced (1)
(ii) CH3OH + 3/2 O2 --> CO2 + 2 H2O (1)
(iii) 3 H2 + 3/2 O2 --> 3 H2O (1)
(e) q = 4389 J, DH = - -399 kJ/mol (3)


3(a) numbers to add 2, 15, 15, 6 (1)
(b) P4 = zero, H3PO4 = +5 (2)
(c) Add up Ar values to show they are different to 5dp (1)
(d)(i) speeds up rate of reaction without being used up (1)
(ii) addition of water (1)
(iii) CH3CH=CH2 + H2O --> CH3CH(OH)CH3, propan-2-ol (2)

4(a) Forms brittle TiC (1)
(b)(i) 2 FeTiO3 + 7 Cl2 + 6 C --> 2 FeCl3 + 2 TiCl4 + 6 CO (1)
(ii) TiCl4 + FeCl3 + 7 Na --> Fe + Ti + 7 NaCl (1)
(c) Cu2+ + Fe --> Cu + Fe2+, Cu2+ ions reduced as they gain electrons (2)
(d) 2 O2- --> O2 + 4e (1)

5(a)(i) Ba + 2 H2O --> Ba(OH)2 + H2 (1)

(ii) reactivity increases (1)

(b) Mg(OH)2 (1)

(c) Barium meal / X-ray tracer, insoluble (2)

6(a)(i) Cl2 --> 2 Cl.
CH2Cl2 + Cl. --> .CHCl2 + HCl
.CHCl2 + Cl2 --> CHCl3 + Cl. (3)
(ii) UV light, Free-radical substitution (2)
(b)(i) CHCl3 + Cl2 --> CCl4 + HCl (1)
(ii) CHCl3 contains C-H bonds, no C-H absorption at 2850-3300 (2)
(c) CFC's - UV light breaks C-Cl bond, makes Cl. radicals
Cl. + O3 --> ClO. + O2
ClO. + O3 --> 2 O2 + Cl. chain reaction
2 O3 --> 3 O2 (4)
(d)(i) CH2=C(F)CF3 (1)
(ii) it contains no C-Cl bonds (1)

7(a)(i) elimination mechanism (3)
(ii) E hex-3-ene (H's on opposite sides) and Z-hex-3-ene (H's on same side) (2)
(iii) Same MF and SF, different arrangement of atoms in space (2)
(b) H2SO4 electrophilic addition mechanism (4)

8(a) Safety - NaOH is corrosive, Environmental - Process 2 uses CO2 from local factory, less CO2 emissions/global warming (2)
(b)(i) Nucleophilic substitution with :OH- (3)
(ii) BCA (3)
(c) Fermentation, 35oC, Yeast, aqueous, anerobic (4)
(d) primary alcohol, acidified potassium dichromate(VI)
CH2(OH)CH2CH2CH2OH + 4[O] --> HOOCCH2CH2COOH + 2 H2O (3)

9(a)(i) Iodine/I2, Cl2 + 2 I- --> 2 Cl- + I2, redox (3)
(ii) silver(I) chloride, Ag+ + Cl- --> AgCl, ppt dissolves (3)
(b)(i) H+ + Cl- --> HCl, HCl (2)
(ii) 2 I- --> I2 + 2e-
H2SO4 + 8 H+ + 8 e- --> H2S + 4 H2O
H2SO4 = oxidising agent, yellow solid = sulfur/S/S8 (4)
(iii) NaOH reacts with H+, equilibrium shifts right to make more H+ and opppose the change
bromine is used in small quantities

[khalidpatel]

YAYYYY markscheme

[TheGirlNextDoor]

(Original post by knocker)
(ii) silver(I) chloride, Ag+ + Cl- --> AgI, ppt dissolves (3)

lol

[jqian]

(Original post by knocker)
UNOFFICIAL MARK SCHEME - please point out any errors (done with paper in front of me and I'm a teacher...)

1(a) steeper line, ending twice as high (2)
(b) less steep line, ending 2/5 as high (2)
(c) steeper line, ending at same level (2)
(d) concentration of reactants decreases with time, hence frequency of collisions decreases as does the rate (2)
(e) 2 H2O2 --> 2 H2O + O2 (1)
(f) The HBr is not used up (1)

2(a)(i) -49 (3)
(ii) it is an element (1)
(b) increases, 4 moles gas --> 2 moles gas, eqilibrium shifts right to oppose the change (3)
(c) increases, reaction is endothermic, equilibrium shifts right to oppose the change (3)
(d)(i) no net carbon produced (1)
(ii) CH3OH + 3/2 O2 --> CO2 + 2 H2O (1)
(iii) 3 H2 + 3/2 O2 --> 3 H2O (1)
(e) q = 4389 kJ, DH = - -399 kJ/mol (3)


3(a) balancing equation (1)
(b) P4 = zero, H3PO4 = +5 (2)
(c) Add up Ar values to show they are different to 5dp (1)
(d)(i) speeds up rate of reaction without being used up (1)
(ii) addition of water (1)
(iii) CH3CH=CH2 + H2O --> CH3CH(OH)CH3, propan-2-ol (2)

4(a) Forms brittle TiC (1)
(b)(i) 2 FeTiO3 + 7 Cl2 + 6 C --> 2 FeCl3 + 2 TiCl4 + 6 CO (1)
(ii) TiCl4 + FeCl3 + 7 Na --> Fe + Ti + 7 NaCl (1)
(c) Cu2+ + Fe --> Cu + Fe2+, Cu2+ ions reduced as they gain electrons (2)
(d) 2 O2- --> O2 + 4e (1)

5(a)(i) Ba + 2 H2O --> Ba(OH)2 + H2 (1)

(ii) reactivity increases (1)

(b) Mg(OH)2 (1)

(c) Barium meal / X-ray tracer, insoluble (2)

6(a)(i) Cl2 --> 2 Cl.
CH2Cl2 + Cl. --> .CHCl2 + HCl
.CHCl2 + Cl2 --> CHCl3 + Cl. (3)
(ii) UV light, Free-radical substitution (2)
(b)(i) CHCl3 + Cl2 --> CCl4 + HCl (1)
(ii) CHCl3 contains C-H bonds, no C-H absorption at 2850-3300 (2)
(c) CFC's - UV light breaks C-Cl bond, makes Cl. radicals
Cl. + O3 --> ClO. + O2
ClO. + O3 --> 2 O2 + Cl. chain reaction
2 O3 --> 3 O2 (4)
(d)(i) CH2=C(F)CF3 (1)
(ii) it contains no C-Cl bonds (1)

7(a)(i) elimination mechanism (3)
(ii) E hex-3-ene (H's on opposite sides) and Z-hex-3-ene (H's on same side) (2)
(iii) Same MF and SF, different arrangement of atoms in space (2)
(b) H2SO4 electrophilic addition mechanism (4)

8(a) Safety - NaOH is corrosive, Environmental - Process 2 uses CO2 from local factory, less CO2 emissions/global warming (2)
(b)(i) Nucleophilic substitution with :OH- (3)
(ii) BCA (3)
(c) Fermentation, 35oC, Yeast, aqueous, anerobic (4)
(d) primary alcohol, acidified potassium dichromate(VI)
CH2(OH)CH2CH2CH2OH + 4[O] --> HOOCCH2CH2COOH + 2 H2O (3)

9(a)(i) Iodine/I2, Cl2 + 2 I- --> 2 Cl- + I2, redox (3)
(ii) silver(I) chloride, Ag+ + Cl- --> AgI, ppt dissolves (3)
(b)(i) H+ + Cl- --> HCl, HCl (2)
(ii) 2 I- --> I2 + 2e-
H2SO4 + 6 H+ + 6e- --> H2S + 4 H2O
H2SO4 = oxidising agent, yellow solid = sulfur/S/S8 (4)
(iii) NaOH reacts with H+, equilibrium shifts right to make more H+ and opppose the change
bromine is used in small quantities

Looks fine apart from 9a)ii), it should be H2SO4 + 8h + 8e- --> H2S + 4H2O

[cuckoo99]

(Original post by Casshern1456)
It is I dunno whether to think I'm stupid for missing out the easy mark or are they just daft for not making it clear and drawing out attention to the questions at the bottom ya know by actually putting lines in for us to WRITE ON.

ye :/ im so ****ing annoyed. those 3 marks could mean the difference between and A and B for me :/ ****