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Date Posted: 07:29:12 11/18/01 Sun
Author: weiying
Subject: chemistry

Although i've dropped chemistry...there are a few tips from my classmates, might be of some use...
If u pple have followed the list closely, Paper 1 should be well-fought.
Now talk about what to focus on for Paper 2:
>(i) Kinetics - all those concepts eg. empirical rate law matched rate law
of rds, Boltzmann plot to explain effect of catalyst and temperature on
rate(RJC Prelim P1 Qn), predict order from data analysis.
>Must do those listed questions WELL.
>
>(ii) Ideal Gases - Assumptions of KE Theory, CONDITIONS for ideality (ie.
high T or low P), FACTORS causing non-ideality (intermolecular forces and
size of particles) (RJC Prelim P2).
>Must do those listed questions WELL.
>
>(iii) Electrochemistry - Well since P1 have not appeared, now very likely
it would come out in P2 and MOST LIKELY IN TM P4 (where u need to do
calculations to substantiate the prediction of the reaction ie. calculate
Eo(cell) values, so Pls take note of the TM Qns that involved this type of
calculations).
>So concepts to take note- H2O2/MnO4- Ecell calculation, define std red
potential, draw Galanic cell set-up, determination of Avogadro's constant,
use Ecell to predict viability of reaction (REMEMBER "energetically feasible
under standard comditions" IMPORTANT)
>Must do those listed questions WELL.
>
>(iv) Periodicity - Again never come out!!!!!!! So take note for P2. Must
know how to explain the IE trend across the period (IMPORTANT CONCEPTS:
Penetrating power of orbitals, Interelectronic repulsion, Effective Nuclear
Charge), may ask to MAP-OUT the IE chart.
>Others - Know bonding, rxn with water, type of oxides, pH, mpt, structure,
solubility of oxides from Na to S (IMPORTANT: MUST KNOW HOW TO MAP-OUT THE
TREND!!!!!)
>Do the Qns WELL.
>
>(v) Group II - Again never come out!!!!!!! So take note for P2. Thermal
stabilities of carbonates or hydroxides, solubility of sulphates- Ksp
calculation- talk about dHsol= dHhyd - LE (actually this was tested in P1,
the one on AlF3 and AlCl3), differential rxn of the metal with water to give
basic solutions.
>
>For (iv) and (v), take note of the various REACTION EQUATIONS with proper
state symbols.
>
>(vi) Organic Chemistry - Since acidity have been tested, focus on basicity
ie amide, amine, phenylamine, electrophilic addition of alkene (remeber to
know the stability of carbocation which would result in different types of
produts formed ie. where the E+ would attack, if aq Br2 used then form
bromohydrin), electrophilic substitution of benzene (IMPORTANT: P1 DO NOT
HAVE BENZENE. SO MUST KNOW- the various directing effects of the gps ; the
reaction conditions to put in a gp onto the benzene ring, focus on
alkylation, nitration, halogenation including the generation of the E+ ; aq
Br2 for phenol and phenylamine), must know iodoform reaction, Fehlings and
Tollens equations for ALDEHYDE; must also know KMnO4 can be used to
determine the position of double bonds in alkene which would lead to the
elucidation of an organic structure; must know NaNO2/HCl/0oC test for 1o
amine and phenylamine; must know the test for phenol.
>
>Now since organic mechanism have not been tested, so take note of E+
addition and E+ substitution. Die die must know.
>
>Must do the list of Qns well.
>
>For P4, go according to the list given and PLS pay emphasis to usine Ecell
calculation to test for feasibility.

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