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
Thank you Ultimaonline for your advice!
I have modified a little of my post after you have posted today. Wonder if melamine or DEHP may come out this year after unfortunate incidents in China?
I can only keep my fingers crossed and pre-empt my student that this year's paper may be more challenging than last year.
It may also be good for students to know the structures of different saccharides, lipids and carbohydrates and even nuclei acids.