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CIE Chemistry AS Practical

Hey guys we just took the AS Chem Practical and we thought it was impossible, we didn't even have time for question 3. What were you guys' titres? We got weird stuff, one end of the spectrum was 40cm^3 and the other was 25 cm^3. And what was the AR of Magnesium?
Original post by Spellingmistakes
Hey guys we just took the AS Chem Practical and we thought it was impossible, we didn't even have time for question 3. What were you guys' titres? We got weird stuff, one end of the spectrum was 40cm^3 and the other was 25 cm^3. And what was the AR of Magnesium?


We got around 27.90cm3
Reply 2
Oh God....It went utterly horrendous!:frown:

First things first, Question 1 - Was it just me or did anyone else out there got the magnesium strip of wrong mass (that wasn't appropriate for the experiment)?

I set up my whole Q1 apparatuses, the inverted cylinder..the clamp..the flask EVERYTHING. I started the experiment. Waited for the Mg to react completely, BUT the hydrogen produced was SO MUCH that it advanced the graduation on the measuring cylinder!! Thats not all. I somehow (by scale and measurements) found out the volume of H2 produced, wrote it down and did the rest of ALL calculations in the first question and finished with my final answer:angry:. But then, when I thought that was the least problem I could have, the supervisor walked up to me and asked me why i didn't ask for another Mg strip of lower mass! JUST LIKE THAT MY WHOLE Q1 WENT INTO COMPLETE WASTE!

I wanna ask a question to all the CIE candidates out there, is it genuinely OK to ask for another mass of something (or even anything that has been clearly officially labeled FB) when you've been officially given a "FB1 Magnesium Strip" to use in the question?:frown:

I mean, how would i have ever known that THAT particular mass of Mg would not be suitable for my experiment! I was completely clueless about the fact that i could ask for another one! It was the fault of the staff who were responsible for providing an appropriate mass of Mg! I requested them for extra time as it was in no possibility my fault, but they denied. There was a lot of talking and stuff which ate good amount of my time.
So, I had to set up and do the WHOLE experiment AGAIN! (''including'' the calculations that followed)
And then ended up getting 19 as the Ar of Mg. Great. Just great.
Since Question 2 was related to Q1, I'm just praying they ecf (error carrried forward) the results and calculations.

Question 2. Started with the titration. Got values of titre around 27cm3 to 30 cm3. I have no idea if those are ok... Due to lack of time, couldn't do the last few parts of questions to in Q2.

Until i reached Question 3, I had so little time (say, 15 - 20 minutes), you can imagine how that might've gone. I hardly did 2 - 3 observations of the first part, and since i was running of out time, couldn't do the rest of the question. BLANK! I had never expected to leave anything blank in p3. :frown:

And thats pretty much what happened with me and a couple of other candidates (whom i could talk to later).:frown::frown::frown:

And just so you know, I did brilliantly in Physics and Biology practicals, therefore I expected everything to go fluently in Chem practical.

I do believe i should have been given extra time. But there wasn't much of a point to argue further with anyone during the exam, as it was the matter of time.
If anyone particularly gave this exam in Jeddah (I don't want to disclose the name of the school), please share your experience if u went through the same as me.
Original post by Random98
Oh God....It went utterly horrendous!:frown:

First things first, Question 1 - Was it just me or did anyone else out there got the magnesium strip of wrong mass (that wasn't appropriate for the experiment)?

I set up my whole Q1 apparatuses, the inverted cylinder..the clamp..the flask EVERYTHING. I started the experiment. Waited for the Mg to react completely, BUT the hydrogen produced was SO MUCH that it advanced the graduation on the measuring cylinder!! Thats not all. I somehow (by scale and measurements) found out the volume of H2 produced, wrote it down and did the rest of ALL calculations in the first question and finished with my final answer:angry:. But then, when I thought that was the least problem I could have, the supervisor walked up to me and asked me why i didn't ask for another Mg strip of lower mass! JUST LIKE THAT MY WHOLE Q1 WENT INTO COMPLETE WASTE!

I wanna ask a question to all the CIE candidates out there, is it genuinely OK to ask for another mass of something (or even anything that has been clearly officially labeled FB) when you've been officially given a "FB1 Magnesium Strip" to use in the question?:frown:

I mean, how would i have ever known that THAT particular mass of Mg would not be suitable for my experiment! I was completely clueless about the fact that i could ask for another one! It was the fault of the staff who were responsible for providing an appropriate mass of Mg! I requested them for extra time as it was in no possibility my fault, but they denied. There was a lot of talking and stuff which ate good amount of my time.
So, I had to set up and do the WHOLE experiment AGAIN! (''including'' the calculations that followed)
And then ended up getting 19 as the Ar of Mg. Great. Just great.
Since Question 2 was related to Q1, I'm just praying they ecf (error carrried forward) the results and calculations.

Question 2. Started with the titration. Got values of titre around 27cm3 to 30 cm3. I have no idea if those are ok... Due to lack of time, couldn't do the last few parts of questions to in Q2.

Until i reached Question 3, I had so little time (say, 15 - 20 minutes), you can imagine how that might've gone. I hardly did 2 - 3 observations of the first part, and since i was running of out time, couldn't do the rest of the question. BLANK! I had never expected to leave anything blank in p3. :frown:

And thats pretty much what happened with me and a couple of other candidates (whom i could talk to later).:frown::frown::frown:

And just so you know, I did brilliantly in Physics and Biology practicals, therefore I expected everything to go fluently in Chem practical.

I do believe i should have been given extra time. But there wasn't much of a point to argue further with anyone during the exam, as it was the matter of time.
If anyone particularly gave this exam in Jeddah (I don't want to disclose the name of the school), please share your experience if u went through the same as me.


IKR it was crazyyy! My volume of Hydrogen produced was more than 250 so I made up a number, 210 cm^3, because we were supposed to get roughly 240 mL theoretically but I figured some gas would be left in vial X. Our mass of Mg was like 0.24 g, it seemed like such a nice number, exactly 0.01 moles, but idk. I don't think you were supposed to ask for a smaller mass of Mg.

For question 2 I got titres between 25 and 27 although there was a good bit of variation which scared me. I also only had about 15 mins left for question 3, rushed in a couple of tests. I found one of them produced gas (the one with a little of both) and tested with a match and it went out, so I put CO2. Did anyone else put that???

I also think the first part of the question was far too time consuming, what with all the setting up of the apparatus, especially considering it was only worth 6 marks or so.

My friend and I also took the physics practical and thought it was easy too but this was just ridiculous.... :angry:
Reply 4
Original post by Spellingmistakes
IKR it was crazyyy! My volume of Hydrogen produced was more than 250 so I made up a number, 210 cm^3, because we were supposed to get roughly 240 mL theoretically but I figured some gas would be left in vial X. Our mass of Mg was like 0.24 g, it seemed like such a nice number, exactly 0.01 moles, but idk. I don't think you were supposed to ask for a smaller mass of Mg.

For question 2 I got titres between 25 and 27 although there was a good bit of variation which scared me. I also only had about 15 mins left for question 3, rushed in a couple of tests. I found one of them produced gas (the one with a little of both) and tested with a match and it went out, so I put CO2. Did anyone else put that???

I also think the first part of the question was far too time consuming, what with all the setting up of the apparatus, especially considering it was only worth 6 marks or so.

My friend and I also took the physics practical and thought it was easy too but this was just ridiculous.... :angry:


True... Physics really was an easy one, and so was Chem (if I had time, I could nicely and correctly solve all the questions) but it just was ridiculous.
Oh I can't possibly answer as to whether the gas was CO2 or not cuz I never got to do it :redface:. Although I did one test for a gas and it turned out to be NH3...
I guess everyone had difficulty in the first question so I'm guessing they'll put a large margin in answers (I hope).
Oh you got a good mass of Mg there. For my first one i got 0.35 g:s-smilie:. Then later the 2nd one i don't remember what it was...
Anyways, I hope the gt are low..

What other subjects are you giving? Are you gonna give Chem and Phy 11?
How'd your paper 2 go?
This exam was definitely one of the hardest I've ever done. Did you all manage to complete the last question? I found it was a very long exam and it was very difficult to identify the ions!!

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