H3 Chemistry Syllabus 2026: What It Covers and Who Should Take It

Topic

Content

SPECTROSCOPIC TECHNIQUES

1.1  Basic Principles of Spectroscopy Content

• Molecular orbital theory

• Electromagnetic spectrum

• Quantisation of energy

• Energy level transitions

1.2  Ultraviolet/visible Spectroscopy Content

• Electronic transitions

• Chromophores

• Molar absorptivity and the Beer–Lambert law

1.3  Infrared (IR) Spectroscopy Content

• Molecular vibrations: stretching and bending

• Characteristic IR absorptions

1.4  Nuclear Magnetic Resonance (NMR) Spectroscopy

• Nuclear spin and energy absorption

• Chemical shift: δ scale, internal reference, electronegativity effects, anisotropic effects, hydrogen bonding

• Calculation of peak area and proton counting

• Spin-spin splitting

1.5  Mass Spectrometry Content

• Ionisation, fragmentation and mass/charge ratio

 • Interpretation of spectra: molecular ion peak, isotopic abundance, fragment ions

MOLECULAR STEREOCHEMISTRY

2.1 Molecular Stereochemistry Content

• Stereochemical projection
•  Isomerism: conformational, cis-trans, enantiomerism, diastereomerism

FURTHER ORGANIC MECHANISMS

3.1 Basic Physical Organic Chemistry

·         The Hammond postulate: relationship between the transition state and the nearest stable species

3.2 Nucleophilic Substitution Content

·         Mechanism: nature of nucleophiles and leaving group, SN1, SN2

·         Kinetics of mechanisms: energy profile, rate law, simple rate equations, orders of reaction, rate constants, stereochemistry, substituent effects

·         Competition between SN1 and SN2

3.3 Elimination Content

·         Mechanism: syn- and anti-elimination, stereoselectivity, regioselectivity, E1, E2

·          Kinetics of mechanisms: energy profile, rate law, regioselectivity

·         E2/SN2 competition: substrate effects, base effects