A few words about Cambridge exam papers 2015

Candidates may note that 2015 Singapore-Cambridge exam papers seemed easier than previous years' papers.

One solvent appeared in Cambridge papers in 2015 and in some prelim papers, so students may read up on solvents such as
ethane (glyme, DME)
C4H10O2 ,

formamide (DMF)
C3H7NO and

dimethyl sulfoxide (DMSO) C2H6OS

For Cambridge papers of 2015, students may like to read up on Group VII (or Group 17) chemistry, sugars (saccharides), nuclear chemistry, organic solvents and polymers.

2015 papers had a disproportionately higher weightage of marks on Group VII (Group 17) chemistry, gases and energetics. Transition metals chemistry appeared relatively little. The planning question was quite surprising as it tested on chemical equilibrium and acid-base titrations.

Students may like to look up on wikipedia on phosgene and its ability to form polymers with another monomer; students may also read up on triglycerides (fats).
Cambridge International Exam Papers of Summer and Winter 2015 are out at xtremepapers.com
You may want to look at them. Two interesting features are that Cambridge favoured a compound Benzene-1,2-diamide. 

I wonder if pyridine, C5H5N, which is a solvent and a weak base, will appear in this year or next year's exams?


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Organic Chemistry - Reaction mechanism

Organic chemistry – Question on reaction mechanism

The above reaction is known as the mechanism of Kolbe reaction.
(a)    Name 2 types of reaction in the mechanism.
(b)    Write an overall equation consisting of 2 stages to represent the mechanism. Sulfuric acid is used in the last stage of the reaction.
(c)    Suggest a solvent to carry out the reaction.


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Note : Cambridge has used some university questions from university textbooks in the recent years' exam papers.

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Substances that teachers may prefer this year

Similar substances have appeared in recent Cambridge papers.
Do you think teachers will prefer these substances this year?

Can you spot enol-keto tautomers, anhydrides, peroxy acid, amide, epoxide, sodium superoxide? Teachers may like sodium peroxide too.

 2017 may see different types of molecules appearing as Cambridge may have younger professors who are so brilliant to set the papers for the new syllabus.

Related links to these molecules:

These heterocyclic aromatic compounds have appeared in MCQ  of 2014 exam papers.