5. Chem 30: Organic Chemistry – This is a very tough course from the Chem department and a continuation of Chemistry 20. It explores basic principles and advanced topics in organic chemistry. The description claims that carbonyl chemistry and pericyclic reactions are covered in great detail–which like fictional words to scare people from this class. Also, the lab element of this course is said to be particularly grueling, which also takes part in keeping Organic Chemistry as one of the hardest concentrations at Harvard.
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