tsfx exam

[roly182]

hey is this supposed to be out already?? Anyone know where to get it? thanks!

[lauzy358]

http://tsfx.com.au/vic/default.htm

Or, for the lazy:
http://tsfx.com.au/vic/Unit%204-2008-CHEMISTRY-Exam-Schools-Paper-FINAL.pdf
http://tsfx.com.au/vic/Unit%204-2008-CHEMISTRY-Exam-Schools-SOLUTIONS-FINAL.pdf

=]

[roly182]

for question 10 on multiple choice, what is stopping C from being the answer?

[bec]

for question 10 on multiple choice, what is stopping C from being the answer?

Yeah, that's a good question...here it is:

 
When a solution containing 3(aq) NH is added, the solid silver chloride rapidly dissolves.

 

QUESTION 10
Which of the following actions would result in an increase in the amount of
undissolved AgCl ?
A Dilution with water.
B The addition of more ammonia.
C The addition of HCl .
D An increase in the atmospheric pressure

A is definitely right, but I see what you mean about HCl.

I think that if they added HCl, it would react with NH₃, effectively removing it. So would that mean the second reaction is driven to the left, which increases the yield of Ag+ and thereby drives the first reaction to the left as well? Can someone explain why this reasoning is wrong?

[roly182]

i just thought about it as increasing the CL- concentration and therefore driving first reaction to the left..
bec what did you think about the difficulty of this paper?

[We Want Peace.]

i just thought about it as increasing the CL- concentration and therefore driving first reaction to the left..
bec what did you think about the difficulty of this paper?

same here.just did this morning

[bec]

i just thought about it as increasing the CL- concentration and therefore driving first reaction to the left..
bec what did you think about the difficulty of this paper?

oh right, that too. I haven't corrected yet but I thought it was probably the hardest I've done so far - i almost didn't finish in time, and i couldn't do some of the questions (which I'll probably be asking about on the forum soon!) did other people find it hard?

[roly182]

yeah it was the hardest of all the ones ive done too...finished with 15 minutes left when i usually finish with about 40. That % efficiency of the calorimeter was wierd.. not how i did it at all. i got around 95% efficient...

[bec]

I got 95.6% for that question.

I'm just correcting now, this is DEFINITELY the worst i've ever done! I don't agree with a few of the answers, either (although its very likely its me that's wrong, not TSFX)

eg. Q6b - in the solutions, it says that it would release MORE energy if it was LESS efficient. How does that work? (i got 2077kj for this one)....actually no, i think i was wrong there...

[We Want Peace.]

yeah. 95.6%
I got that too.
I dont understand why they were using 38.08KJ / 44.8

[julezian]

i didn't think it was too bad 80% lol
tsfx assumes a tonne of knowledge and their questions also just assume you get the,
so if you didn't understand them too well i wouldnt worry coz vcaa should be alot clearer in their wording etc

[205ism]

The TSFX exam was horribly hard, I got 58/82, and all my others have been above 85%, and just got 78/84 for the IARTV paper, so I'm not feeling so depressed now.

[roly182]

yeah its been the hardest for me too. Ive gotten close to, if not full marks on all the other trials and the sample exam but lost 5 marks on this one. stupid tsfx