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.
2019 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.