15 May 2008

AS: Chemistry P31

First A Level exam, one of the most challenging of all...... Chemistry Practical!

Was kinda nervous to sit for this exam. It starts off with something happened last night....
A nightmare I had, dreaming that I weirdly missed the exam by an hour eventhough I arrived in the college earlier. You know, dreams are unexplainable.... it's just wicked! How on Earth I'll be late for the exam if I've arrived earlier?
Either way, it is even weirder I dream of myself just woke up from my desk back in secondary school. I was, WTF?!? Everyone is in their uniform while I'm in my usual college-wear.
Wicked.... I know my secondary school is not really far from the college in reality, but to had myself woke up at the other corner of the world is kinda absurd lol.

Anyway the nightmare serve as a joke more than a haunting experience. I wasn't late for today's exam. :D

The exam itself, is wicked too.

Thankfully we've done last year's practical as a mock test, and this year's paper doesn't run far from last year's format.

Like what I did in the mock test, I start off with Question 2 first as I dont wanna fight with my classmates over the chemical reagents later. Question 2 is, salt analysis.

Given FA4, FA5 and FA6. You're required to identify which is NH4I, Al2(SO4)3 and Zn(NO3)2.

The test for the ions are pretty much simple, kinda straight forward. Luckily only 3 of them involved, or else I might get confused with the solutions (as I did in the mock test when playing with 4 solutions).

The weird thing is.... I couldn't get a positive result for testing NH3 gas that will evolved theoretically.... NO3- and NH4+ compounds will definitely give off the gas while heating, weird eh.... Even if I dont test it with damp red litmus paper, I can still smell the distinctive ammonia fume, which I dislike (want to know how it smells, try to goto a toilet that haven't been washed for weeks... yucks!).

Thankfully, I'm able to finish this Q2 within an hour time. Only then I flip to the pages in front to deal with Q1.

Question 1 is titration with a wicked graph, yeah wicked.



It's something unusual that we wouldn't do in normal practicals.

Part C of Q1 killed me lots of precious time as I couldn't figure out how to get the weird volume they asked. In the end I flipped to the next page, and was surprise to see they did give a hint on doing the next part even though I cant get the volume in part C. They even give you a range of values that possibly is the volume you'll need to find in C, wicked....

I managed to draw the graph, but that also took me quite some time to do it because it's an unusual graph like I showed above.

Too bad I dont have enough time to finish off the calculation part. It shouldn't be that hard, but when it ask me to calculate the molecular mass Mr, I was freaked up because of the complexity of the solution.... (NH4)2.FeSO4, this is the molecule if I remembered it correctly. I know calculating Mr is very easy, but no matter how easy it is you basically just can't do it if the invigilator took the paper from you already....

Sigh, 8 marks gone. I just hope I can score well in the rest of Q1 and Q2.....
My only hope is that Q2 will get a perfect mark. :)

Next Monday gonna have Physics 2, another wicked paper. Physics is an interesting subject but sometimes it's just wicked, yeah wicked..... Everything is wicked!!

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