External Exam Moral Support! (+ help with calculations questions)

[piperfred]

Hi everyone,

I, like many others I'm sure, is mega struggling with studying for chemistry! That mock exam really threw me for a loop, so I'd love to hear how others are tackling their study, particularly if the mock didn't go so great for you either.

One thing I'm really struggling with is answering questions that involve calculations, like complex stoichiometry questions for example. Does anyone a) have any tips and b) know where I could access more complex calculations questions like those found in the mock exam?

Thank you so much in advance and I'd be super grateful for any tips you have
Piper

[Bri MT]

Hi!

What about calculation questions is throwing you off? Interpretation? Knowing what steps to take? Losing which values go where?

One thing I highly recommend if the long ones in particular are throwing you off is trying to be really clear and explicit in your working. E.g. rather than just n = 2.0 using n(HCl) = 2.0 mol. Having clearer working helps you stay on track and think more logically through the question as well as making it easier for someone marking you to see your working. 

For questions I recommend looking at past exams in other states. Where and what years you look at will influence the content but you should find it fairly easy to find questions relevant to you - just check the syllabus or ask if you are unsure whether a question would fit in Qld.

For example, here's where you can find:
Victorian past exams (go to old exams if you want to practice things like pH, pKa etc.)
NSW past exams


E.g. the 2009 Exam 2 from Victoria you should skip a couple of questions near the end but most of it is relevant including calculation questions.


Do you know how to use things like ICE / RICE tables to simplify calculations for equilibrium questions?


I hope this helps & remember that you do still have some time to learn from your mocks - lots of people will be feeling taken aback by them and you're definitely not alone

[piperfred]

Thanks for replying! I'll definitely check out those resources.

I'm pretty good with ICE tables, but the more unfamiliar questions (e.g. finding concentrations or pH from titration curves) are really tricky for me, I'm struggling to know where to start.

[Bri MT]

Thanks for replying! I'll definitely check out those resources.

I'm pretty good with ICE tables, but the more unfamiliar questions (e.g. finding concentrations or pH from titration curves) are really tricky for me, I'm struggling to know where to start.

No worries!

If you're absolutely lost in a chem question sometimes seeing if you can find something in mols can then help you translate across to something else you need.

For example:
pH <-- pH = -log([H+]) --> concentration of H+<-- n=cv --> mols of H+ <-- balanced chemical reaction --> mols of something else <-- n = m/M  or n = cv  --> mass or concentration

if you're having trouble understanding how to read pH from a titration curve make sure you know how to identify the point you're interested in (i.e. initial, equivalence point, ph = pKa, or final) and do some practice reading this off graphs.

I hope this helps, please feel free to follow up with any additional questions or comments etc.