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Did anyone take AS CIE Chemistry exam today?

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Reply 140
Avatar for A.S.J
A.S.J
2
Guys those who did practical paper 32 for Chemistry do you remember your titration reading? mine was 18. but my friend and thegirl sitting next to me had 23.
but my titre was so accurate, the blue changed to pale yellow and I stopped. :frown:
Reply 141
Avatar for InkRed
InkRed
7
Original post by A.S.J
it is the way Ink red did but the calculation is wrong.
write the equation s8+8o2------> 8so2 and draw the Hess cycle with S8 to 8S just like how Ink red did.
then the calculation part is
2232+[4*496]+16x=-2376
-2376-[6200]=16x
x=536


hope you get it.


Correct me if I'm wrong but since we go around in Hess' cycle the sign for 16x would change. The way you do it results in a negative bond enthalpy which shouldn't be so. What do you think?
Reply 142
Avatar for InkRed
InkRed
7
Original post by A*girl
I messed up the calculations of both the questions. The question based on qualitative analysis went surprisingly well. Also, what was your titration reading?


Were most of your observations along the lines of "no observable change?"
All the best for result day!
Reply 143
Avatar for A*girl
A*girl
Original post by InkRed
Were most of your observations along the lines of "no observable change?"
All the best for result day!

Yeah, FB5 had the most "no change visible" and what was the cation in fb8? The solid we heated? Nothing happened
Reply 144
Avatar for InkRed
InkRed
7
Original post by A*girl
Yeah, FB5 had the most "no change visible" and what was the cation in fb8? The solid we heated? Nothing happened


I didn't have a lot of time to heat it properly. Most people wrote one of Mg2+, NH4+
The supervisor in our lab had a titre of 26.50 (we interrogated him after the exam)
Reply 145
Avatar for A*girl
A*girl
Original post by InkRed
I didn't have a lot of time to heat it properly. Most people wrote one of Mg2+, NH4+
The supervisor in our lab had a titre of 26.50 (we interrogated him after the exam)

Most of us wrote no cation and carbonate as the anion. Out titre was between 27 and 28
Original post by InkRed
I didn't have a lot of time to heat it properly. Most people wrote one of Mg2+, NH4+
The supervisor in our lab had a titre of 26.50 (we interrogated him after the exam)


Mg2+? I don't think so. There was NO3-, Mn2+, NH4+
Reply 147
Avatar for InkRed
InkRed
7
Original post by A*girl
Most of us wrote no cation and carbonate as the anion. Out titre was between 27 and 28


I see. That's fine too I suppose
Reply 148
Avatar for InkRed
InkRed
7
Original post by maria.x
Mg2+? I don't think so. There was NO3-, Mn2+, NH4+


probably so. as i said earlier identification didnt go too well for me
Original post by InkRed
probably so. as i said earlier identification didnt go too well for me


All of the answers are confirmed by my teacher. Too bad I didn't ask her what FB5 was, I wrote Iodine as it was black but others thought it was Aluminium, which makes sense as it was kind of a metal. What did you get?
Reply 150
Avatar for InkRed
InkRed
7
Original post by maria.x
All of the answers are confirmed by my teacher. Too bad I didn't ask her what FB5 was, I wrote Iodine as it was black but others thought it was Aluminium, which makes sense as it was kind of a metal. What did you get?


Was it the one i
Original post by InkRed
Was it the one i


Yes, I suppose? It was the first part.
Reply 152
Avatar for InkRed
InkRed
7
Original post by maria.x
Yes, I suppose? It was the first part.


most kids wrote Ag+...i think. I dont remember clearly
Reply 153
Avatar for ZK123
ZK123
our supervisor got 21.5, how was ur paper overall?
Reply 154
Avatar for ZK123
ZK123
Original post by A.S.J
Guys those who did practical paper 32 for Chemistry do you remember your titration reading? mine was 18. but my friend and thegirl sitting next to me had 23.
but my titre was so accurate, the blue changed to pale yellow and I stopped. :frown:

our supervisor got 21.5, how was ur paper overall?
Reply 155
Avatar for A.S.J
A.S.J
2
Original post by InkRed
Correct me if I'm wrong but since we go around in Hess' cycle the sign for 16x would change. The way you do it results in a negative bond enthalpy which shouldn't be so. What do you think?


It does but we can ignore the -ve sign as all the answers given are in positive.
Reply 156
Avatar for A.S.J
A.S.J
2
Original post by ZK123
our supervisor got 21.5, how was ur paper overall?


:frown: Idk i did it three times and i got 18 and some. Somethinf i dont remember.
It was okay but the last question was weird. Like it was soo many observations and all. And the nitrates was weird.
I didnt have enough time to test F10 so i just tested F9 . F9 was the one tgat didnt give gas right? Nitrite i think. So i wrote the other one for F10
And the second question how did you guys do it?
Reply 157
Avatar for InkRed
InkRed
7
Original post by A.S.J
It does but we can ignore the -ve sign as all the answers given are in positive.


And so we both mean the same thing=))
Original post by alyoan tariq
yes i did and dont even ask about it !!!1:frown::frown:
it was a hectic
1) it was too long
2) where did they get questions of cations and anions from i mean like srsly whats wrong wid u guys ?!!!!!
3) the inverted thingy what was wrong with it ...i mean for me the whole thingy got empty
i mean measuring cylinder
and plus i read the measuring cylinder in the wrong direction
and i left like a few questions as in the first question calculation and the estimated error plus the identifying the FB6 cation and anion
although i had an idea it was nitrate but im so dumb i dint write it down ?!!!!!!! omg i feel like killing myself

Original post by A.S.J
Guys those who did practical paper 32 for Chemistry do you remember your titration reading? mine was 18. but my friend and thegirl sitting next to me had 23.but my titre was so accurate, the blue changed to pale yellow and I stopped. :frown:
No Idea why you all think the paper was hard.:confused: The paper went great for me! :biggrin: The first two questions were ditto copy from the specimen paper. The calculation was simple too. My titre was 19.35 cm3 and my friends got similar results in the range of 19cm3 to 22cm3 , but I think everyone wont get the same value as we all had different masses of Magnesium ribbon. I agree the qualitative part was a BIT tough but that was fine too.FB5 was AluminiumFB6 anion was nitrate and cation we cannot decide as the evidence was inconclusive. FB7 was Al2(SO4)3FB8 was MnCl
Original post by alyoan tariq
yes i did and dont even ask about it !!!1:frown::frown:
it was a hectic
1) it was too long
2) where did they get questions of cations and anions from i mean like srsly whats wrong wid u guys ?!!!!!
3) the inverted thingy what was wrong with it ...i mean for me the whole thingy got empty
i mean measuring cylinder
and plus i read the measuring cylinder in the wrong direction
and i left like a few questions as in the first question calculation and the estimated error plus the identifying the FB6 cation and anion
although i had an idea it was nitrate but im so dumb i dint write it down ?!!!!!!! omg i feel like killing myself


i did the v31 , cambridge gave us wrong concentrations for the experiments and we couldnt do the titration , no1 had a change in the colour , so we were in a rush to repeat the 2 experiments from the begining , only half an hour was left... it went pretty bad , i hope they will be lenient with the marking

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