| Haber–Weiss reaction |
| haem |
| half-chair |
half life,  |
| half life of a radionuclide |
| half-peak potential |
| half thickness in radiochemistry |
| half-wave potential |
| half-width of a band |
| halirenium ions |
| halochromism |
| haloforms |
| halohydrins |
| halonium ions |
| halophiles |
hamiltonian operator  |
| Hammett acidity function |
| Hammett equation (Hammett relation) |
| Hammond–Herkstroeter plot |
| Hammond principle (Hammond postulate) |
| handedness |
| Hansch analysis |
| Hansch constant |
| Hantzsch–Widman name |
| hapten |
| hapto |
| hard acid |
| hard amorphous carbon films |
| hard base |
| hard-sphere collision cross section |
| harmonic frequency generation |
| harmonic mean |
| harpoon mechanism |
| hartree |
| Hartree energyconstant |
| Haworth representation |
| hazard |
| haze in atmospheric chemistry |
| haze horizon in atmospheric chemistry |
| health surveillance |
heat,  ,
 quantity |
heat capacity,  quantity |
heat capacity of activation,  quantity |
heat flux,  quantity |
| heavy atom effect |
| heavy atom isotope effect |
| heavy water |
| hectoSI unit prefix |
height equivalent to an effective theoretical plate
( )
in chromatography |
height equivalent to a theoretical plate ( )
in chromatography |
| helicenes |
| helicity |
| helion |
| helium–cadmium laser |
| helium dead-space in colloid and surface chemistry |
| helium ionization detector in gas chromatography |
| helium–neon laser |
| helix |
| helix residue in a polymer |
| helix sense |
Helmholtz energy (function),  quantity |
| hemes (heme derivatives) |
| hemiacetals |
| hemiaminals |
| hemiketals |
| hemileptic |
| hemins |
| hemochromes |
| hemodialysis |
| hemoglobins |
| Henderson–Hasselbalch equation |
| henryunit |
| Henry's law |
| Herkstroeter plot |
| hertzunit |
| Herz compounds |
| hetarenes |
| hetaryl groups |
| hetarynes |
| heteroalkenes |
| heteroarenes |
| heteroaryl groups |
| heteroarynes |
| heterobimetallic complex |
| heterochain polymer |
| heteroconjugation |
| heterocumulenes |
| heterocyclic compounds |
| heterocyclyl groups |
| heterodetic cyclic peptide |
| heterodisperse |
| heteroexcimer |
| heterogeneity in analytical chemistry |
| heterogeneous catalysis |
| heterogeneous diffusion rate constant
in electrochemistry |
| heterogeneous membrane electrode |
| heterogeneous nucleation |
| heteroleptic |
| heterolysis (heterolytic) |
| heterolytic bond-dissociation energy |
| heterolytic dissociative adsorption |
| heteropolysaccharide (heteroglycan) |
| heterotactic polymer |
| heterotactic triads in polymers |
| heterotopic |
| heterotrophic (organisms) |
| heterovalent hyperconjugation |
| hexagonal graphite |
| hexahedro- in inorganic nomenclature |
| hexaprismo- in inorganic nomenclature |
| hidden return |
| high-spin |
| higher-order transition |
| highly oriented pyrolytic graphite |
| high-pressure graphitization |
| high-pressure mercury lamp (arc) |
| high resolution energy loss spectroscopy (HRELS) |
| Hildebrand parameter |
| hindered rotation |
| histones |
| Hofmann rule |
| hold-back carrier |
| hold-up volume in chromatography |
hold-up volume (time),  ,
in column chromatography |
| hole burning |
| hole transfer |
| holoenzyme |
| Holtsmark broadening of a spectral line |
| homo |
| homoaromatic |
| homochain polymer |
| homochiral |
| homoconjugation |
| homocyclic compounds |
| homodetic cyclic peptide |
| homogeneity in analytical chemistry |
| homogeneous catalysis |
| homogeneous membrane electrode |
| homogeneous nucleation |
| homogeneous nucleus |
| homoleptic |
| homolysis (homolytic) |
| homolytic dissociative adsorption |
| homomorphic |
| homopolymer |
| homopolymerization |
| homopolysaccharide (homoglycan) |
| homotopic |
| horizontal elution (horizontal development)
in planar chromatography |
| host |
| host-vector system |
| hot atom |
| hot cell |
| hot ground state reaction |
| hot quartz lamp |
| hot state reaction |
| hourunit |
| Hückel (4n + 2) rule |
Huggins coefficient,  quantity |
| Huggins equation |
| humidity in atmospheric chemistry |
| Hund rules |
| Hush model |
| HWHM (Half Width at Half Maximum) |
| hybridization |
| hybridoma |
| hydration |
| hydrazide hydrazones |
| hydrazide imides |
| hydrazides |
| hydrazidines |
| hydrazines |
| hydrazinylidenes |
| hydrazo compounds |
| hydrazones |
| hydrazonic acids |
| hydride |
| hydro |
| hydrocarbon cracking |
| hydrocarbons |
| hydrocarbylene groups |
| hydrocarbyl groups |
| hydrocarbylidene groups |
| hydrocarbylidyne groups |
| hydrocarbylsulfanyl nitrenes |
| hydrocracking unit |
| hydrodynamically equivalent sphere in polymers |
| hydrodynamic volume in polymers |
| hydrogen |
| hydrogen bond |
| hydrogen gas electrode |
| hydrolases |
| hydrolysis |
| hydrometeor in atmospheric chemistry |
| hydron |
| hydroperoxides |
| hydrophilic |
| hydrophilicity |
| hydrophobic interaction |
| hydrophobicity |
| hydropolysulfides |
| hydrosphere in atmospheric chemistry |
| hydrosulfides |
| hydroxamic acids |
| hydroximic acids |
| hydroxylamines |
| hygrometer |
| hygrometry (moisture analysis) |
| hyperchromic effect |
| hyperconjugation |
| hypersatellite in X-ray spectroscopy |
| hypho- |
| hypochromic effect |
| hypo-phase |
| hypsochromic shift |
| hysteresis |
