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2ndt0m3h

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For questions 13, A and B both satisfy that a rapid increase would occur, however the answer is A as the equilibrium always decreases in the concentration after a rapid increase.
 

photastic

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For questions 13, A and B both satisfy that a rapid increase would occur, however the answer is A as the equilibrium always decreases in the concentration after a rapid increase.
Lol, its B refer to the diagram of 2009 Q23
 

2ndt0m3h

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The question 23 from 2009 shows that CO has been removed from system thus indicating the rapid decrease. So to make up for some of the lost CO the equilibrium shifts to right hence why the concentration of CO increased again.
 

riri109360

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Damn it! I accidentally put B instead of A for question 9! :(
I think I got 18/20
 

bale

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1)d
2)a
3)b
4)c
5)c
6)b
7)c
8)b
9)a
10)c
11)a
12)c
13)b
14)d
15)d
16)b
17)a
18)d
19)b
20)d

Those should get you 20/20
cross checked with the smart people
 

photastic

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The question 23 from 2009 shows that CO has been removed from system thus indicating the rapid decrease. So to make up for some of the lost CO the equilibrium shifts to right hence why the concentration of CO increased again.
Hence it is B since the shape remains the same
 

bale

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when u half the volume pressure INCREASES so it shifts to the side with the least GASEOUS MOLES which is the right (where ammonia is) therefore its concentration increases. So i think B
 

2xL

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when u half the volume pressure INCREASES so it shifts to the side with the least GASEOUS MOLES which is the right (where ammonia is) therefore its concentration increases. So i think B
13 is DEFINITELY B.
 

tomnomnom696

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13b its just the haber process. volume decrease means increased pressure which favours forward reaction and yield so ammonia concentration increases
 

dan964

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answers, confirmed with my entire grade, including those ranked higher than me:

1. D - it is not B (which I put stupidly) and the rest are clearly wrong because ozone is not even in those layers
2. A - lowest locant must be on "bromo" and then "fluoro" not the other way around.
3. B - by elimination, Arrhenius was hydrogen ions, Davy was hydrogen and Lavoisier was oxygen
4. C - by elimination, A is clearly wrong, B is not cracking it is polymerisation, D is not breaking up larger hydrocarbons
5. C - by elimination, A & B are both wrong as there is not double bond in the reactant, D is wrong as well
6. B - (not exactly sure, please confirm), because all values are the lowest except for dissolved oxygen which is good. D is wrong
7. C - by elimination, D is wrong because ammonia is pink in phenolphthalein, and A & B are wrong because they are not yellow in methyl red.
8. B - make sure to note temperature decrease, ph goes up, therefore [H+] goes down. D is wrong because think it about the chemistry of ionisation.
9. A - because Y can't be an isomer with any of the other options eliminating B, C and D
10. C - because either H2O and OH- are paired or HOCl and OCl- are paired. C is the later the rest are wrong.
11. A (I put C, C is wrong because A is not a coordinate covalent bond)
12. C - A & B are wrong, pH is a logarithmic scale, and also D is wrong it is [H+] you are after.
13. B (I put A) - A is wrong because it should dip up, C & D are clearly wrong. The vertical line is all substances change that much.

14. D - use the formula makesure to include the negative
15. D - convert each to moles, the most moles of substance is the biggest i.e. D. All the reactions are 1:1.
16. B - check the oxidation numbers for A & D it goes up, for C it doesn't change, therefore B is correct
17. A - chromate is reduced, and SO2 is oxidised therefore A. Not B because the oxidiation potential of SO2 is not 0.16 but -0.16
18. D - compare the structures, A to C are all inconsistent with the diagram given above.
19. B - calculation
20. D - can't be A or C because think Haber process exothermic reaction, lower temperature better. as pressure goes up, shifts to the right, i.e. side with less molecules, therefore B is wrong.
 
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pheelx3

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omg... got question 9 wrong
what a fucking joke...

don't laugh i can't count carbons...
 
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Can you guys please stop talking about 13. I had D, when I even wrote that a decrease in volume = an increase in pressure. But then for some reason I drew an arrow towards the left hand side of the reaction...............................................

Worst thing is that it wasn't even a hard choice for me between C and D, and everyone seems to be debating that curve.
 

zhertec

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Can you guys please stop talking about 13. I had D, when I even wrote that a decrease in volume = an increase in pressure. But then for some reason I drew an arrow towards the left hand side of the reaction...............................................

Worst thing is that it wasn't even a hard choice for me between C and D, and everyone seems to be debating that curve.
You think that's bad? I got Q15 wrong cause I cannot fkin differentiate which is heavier, 2 sodiums or 1 sodium and 1 Hydrogen -.-
 
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you think that's bad? I got q15 wrong cause i cannot fkin differentiate which is heavier, 2 sodiums or 1 sodium and 1 hydrogen -.-
I got that wrong because i can't divide. (That was meant to be written in all caps)
For some retarded reason I thought that the one with the heaviest molar mass would be the answer.........

Also, I lost my calculator after the exam and life sucks. Actually i'm pretty sure the examiner took it...
 
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