Information for those aiming for a distinction in H2 chemistry
this year:
This post is done with many inputs from Ultimaonline. Thank
you so much Ultimaonline.
Last year's H2 Chemistry paper may be the toughest paper in the
last 20 years of exam history.
Good Knowledge to learn if you are aiming for a distinction in
chemistry:
Destruction of ozone by CFC mechanism in the chapter of
halogenalkanes
pKa of amino acids and how they protonate/deprotonate in
acidic/alkaline medium
Unit cells - found in chemical bonding of textbooks. It is out of
syllabus but came out last year in the exam.
Fuel cell – practise prelim papers for novel fuel cells
(Electrochem chapter)
Transition metal – absorption spectrum, colours of
transition metal ions and their compounds, eg. Colour of [CuCl4]2-
complex. (Cambridge loves this!) Reaction of copper(II) ions with
dilute and concentrated hydrochloric acid. Colours and chemistry of
manganese, vanadium and chromium compounds.
Bond length, delocalisation of electrons in resonance structures ,
hybridisation
Formal charges in drawing Lewis structures - chemical bonding
Practical organic chemistry – eg. How Reflux process is
actually done, separating organic products from their impurities,
apparatus for performing organic experiments
Grignard Reagent – Organic chemistry. Read up in an organic
chemistry textbook
Polymerisation – Organic chemistry. It is out of syllabus but
appeared in last year’s exam paper
Nuclear chemistry – alpha and beta radiation. Out of syllabus but
appeared in exam paper. This chapter is found in Peter Cann and
Peter Hughes "Chemistry" textbook.
Practical inorganic experiments – eg. Nickel ions with EDTA
titrations
Practical physical experiments – eg. Enthalphy change of
reaction, kinetics
Reaction of halogenoalkanes with sodium ethoxide (E1 / E2 versus
Sn1 / Sn2 reactions); Williamson Ether synthesis
addition-elimination mechanism for nucleophilic acyl
substitutions
Enols & Enolates (iodoform mechanism)
Imines & Enamines (2,4-DNPH mechanism)
Nucleophilic Acyl Substitution (addition-elimination mechanisms
involving : esters, amides, acyl halides)
Ethers & Epoxides (mechanisms)
Organic Chemistry Redox reactions (mechanisms for reduction,
oxidation states within organic compounds)
Azo-dye formation and diazonium salt formation (mechanism)
Arrow pushing in organic chemistry mechanisms
Dienes (resonance and bond lengths)
Hofmann degradation of amides
Friedal-Craft alkylation and acylation of benzene (including
mechanisms)
Diels-Alder reaction (found in university organic chemistry
textbook from your school library)
The differences between reducing agents such as LiAlH4, NaBH4
and hydrogen gas with nickel / palladium / platinum catalysts
Solubility of Group II hydroxides and sulfates. (Inorganic
chemistry)
Reverse Osmosis and water treatment
Hydrogen fuel cell
Fullerenes, buckminsterfullerene (found in general chemistry
textbook)
Simple Nanotechnology
Conformation of cyclohexane (found in organic chemistry
textbook)
Alkynes and sp hybridisation
All the best for your prelim exams!
Note : This thread is highly compacted and composed in a limited
amount of time and I will be glad to answer your queries or
elaborate. Ultimaonline is highly experienced and I believe he will
be glad to help too.
chemguide7 aka simple_minded
Ex-MOE teacher
http://alevelchemistrysg.blogspot.com