75% overall (P1 + 2 + 3 + SPA) is pretty safe. Most years the
distinction grade hovers around 75% for H2 Chem, give or take a
couple of % points. You just gotta use your stronger papers to
compensate for your weaker papers / SPA. Paper 3 is actually easier
to score than Paper 2, because of 2 reasons : 1) You get to choose
your best 4 out of 5 qns to answer from. Choosing wisely makes all
the difference between an A and a B grade. 2) Paper 2 has the
compulsory Planning Qn, which is impossible to predict, difficult
to study for, and time-wasting (if you don't know what to write, be
exam-smart and just skip the question, rather than waste valuable
time, considering that most students can't even complete the entire
Paper).
So if the paper is challenging>it should fall around
71-72%.That's a 68%(p1,2,3) with a 90% SPA rating.
Like what I mentioned above,time is still an issue no matter how
many papers I practised thus far. For the recent prelims,I was
compelled to skip the last portion of the question for the 4
questions,ranging from as high as 2 to 5marks in order to
compensate with the lost time.
However,what I learnt is,if you can't beat the clock,then don't.
Skip those that take up too much time. Eg a ridiculous explaination
question worth 2 marks for a reaction/intermediate question worth
as high as 5marks!
I am not so sure of my current standard because the school paper
3 is rather challenging!!
It wasn't the hardest,but I am sure that I learnt quite a fair
bit or two