GT for Chemistry paper 22 AS.

[good man12]

a reasonable expected GT:
P1 : 32=A, 28=B
P2: 46/47=A, 40=B
P33: 26/27=A, 23=B

 

[Rockingmind_m6]

Dat reaction ws not an equilibrium one

Actually, my original comment started off as -
"Paper 21 - We had somewhat the same question,..." (we had an equilibrium though and it was about methanol synthesis)
and the second sub-question had a part relating to the equilibrium yield and the forward reaction being exothermic.
I edited it a few minutes later, because the 24 hours hadn't passed yet, sorry for any inconvenience.

 

[Nisrit Pandey]

35 in P12, 53 in P22 and 16 in P33.........Will these marks in chemistry fetch me an A in AS?​

yeah ! my friend once got E in his practical A in both the papers and he also got A

 

[ibadsiddiqi]

If you've given the paper this year you'd know the expected thresholds. What do you think would become of these marks?

There is a possibility of getting an A. Almost everyone i know gave really crappy practicals. Ur paper 1 and 2 marks are all right they will be more than the GT. So yea you can get an A. But it wont be a high A

 

[raihan1904]

i saw in a site that the optimum temp for CO + H2-> CH3OH rxn is 250c n in xam it was 600K(600-273=373c) so its a comparatively higher temp. so increasing temp increases rate of rxn!!

 

[raihan1904]

Normal conditions are room temperature (around 25degrees) and 1 atomsphere or pressure. The conditions quoted were both higher, way high. So yeah, the rate of formation of methanol would increase in all cases. And for the UPTEENTH TIME, the second reaction was NOT a reversible reaction!!!!! (this is for those who adamantly keep sayin it's an equilibrium).

but the reaction (of methanol forming from CO n H2) is reversible in most of the sites!!

 

[Nisrit Pandey]

but the reaction (of methanol forming from CO n H2) is reversible in most of the sites!!

Even if it was reversible in real life ! in our paper it was not given reversible that means you cannot apply equilibrium the question clearly in bold letters asked for effect on RATE OF FORMATION OF Methanol which is increased by increasing all of the given conditions : temperature, pressure and catalyst

 

[aditya avhad]

a reasonable expected GT:
P1 : 32=A, 28=B
P2: 46/47=A, 40=B
P33: 26/27=A, 23=B

This should be it. Nothing more!! GOD HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[raihan1904]

Even if it was reversible in real life ! in our paper it was not given reversible that means you cannot apply equilibrium the question clearly in bold letters asked for effect on RATE OF FORMATION OF Methanol which is increased by increasing all of the given conditions : temperature, pressure and catalyst

yeah i knw dat.. but in the sites its also given that the operating temp of the rxn is 250c n in exam it was 373c, so incresing temp increases rate is correct i guess!!! although the head of our centre's chem dept. said its a low temp n rate will be less like the habers process!! so im makin surr

 

[angelicsuccubus]

Do any of you have a markscheme for p12? I really wanna check my answers.. cause practical sucked and p1 Im not sure

 

[raihan1904]

Do any of you have a markscheme for p12? I really wanna check my answers.. cause practical sucked and p1 Im not sure

its not released yet by CIE!! most proably by sept. u might get it but its too long

 

[Nisrit Pandey]

yeah i knw dat.. but in the sites its also given that the operating temp of the rxn is 250c n in exam it was 373c, so incresing temp increases rate is correct i guess!!! although the head of our centre's chem dept. said its a low temp n rate will be less like the habers process!! so im makin surr

yeah the increase pressure and temperature reduce yield not the rate of reaction(it is always increased) due to more successful collisions

 

[raihan1904]

tnx, the paper was really easy right!!

 

[aaditya menon]

guyz check this http://en.wikipedia.org/wiki/Flame_test

it says phosphorous has a blue-green flame, does that count? what if i didnt write sodium and wrote P instead

 

[angelicsuccubus]

its not released yet by CIE!! most proably by sept. u might get it but its too long

lol no I meant, may be someone wrote down the answers after the exam cause I know people tend to take the papers from their centres and re do them .. sigh

 

[angelicsuccubus]

guyz check this http://en.wikipedia.org/wiki/Flame_test

it says phosphorous has a blue-green flame, does that count? what if i didnt write sodium and wrote P instead

it wasn't a flame test, it was, a chloride of which element from period 3 burns with a coloured flame?
http://www.kyantec.com/Tips/flame_colorers_for_firewood.htm
FLAME COLOR CHEMICAL
Blue Copper chloride
Carmine Lithium chloride
Green Copper sulfate
Orange Calcium chloride
Purple Potassium chloride
Red Strontium chloride
Yellow Sodium chloride (table salt)

 

[raihan1904]

lol no I meant, may be someone wrote down the answers after the exam cause I know people tend to take the papers from their centres and re do them .. sigh

but their answers cud also be wrong!!

 

[littlecloud11]

damn.. thnx nbtw, do you know aboutany of the other doubts ive highlighted?
thnx again

The sodium answer was correct. alkene + conc. KMnO4 gives HO2CCO2H
And for the empirical formula you'll lose one mark. the answer mark.

 

[angelicsuccubus]

but their answers cud also be wrong!!

yeh true, but it's like a crazy curiousity to compare and find satisfaction, right?

 

[littlecloud11]

dude actually it was q.4. i said it wrong it was q.4 of paper 22 in whch i drew the whole structures of all the organic compounds in the boxes.

And i meant to say q4 too. sorry.