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960 terms · page 19 of 40
High-Performance Liquid Chromatography
A technique in which a liquid mobile phase is pumped at high pressure through a column of very fine stationary phase.
Analytical Chemistry & SpectroscopyHigh-Resolution Mass Spectrometry
Mass spectrometry capable of measuring mass to four or more decimal places, allowing molecular formulae to be determined.
Chemical Bonding & Molecular StructureHOMO and LUMO
The highest occupied and lowest unoccupied molecular orbitals, which together govern a molecule's reactivity and spectroscopy.
Chemical Kinetics & CatalysisHomogeneous Catalysis
Catalysis in which the catalyst is in the same phase as the reactants.
Chemical EquilibriumHomogeneous Equilibrium
An equilibrium in which all the reacting species are present in the same phase.
Foundations of ChemistryHomogeneous Mixture
A mixture whose composition and properties are uniform throughout, with no visible boundary between the components.
Organic ChemistryHomologous Series
A family of compounds sharing the same functional group and general formula, with successive members differing by CH₂.
Biochemistry & Polymer ChemistryHormone
A chemical messenger released by one tissue that regulates the activity of cells elsewhere in the body.
Atomic Structure & PeriodicityHund's Rule of Maximum Multiplicity
The rule that electrons occupy degenerate orbitals singly with parallel spins before any orbital is doubly occupied.
Chemical Bonding & Molecular StructureHybridisation
The mixing of atomic orbitals on the same atom to form an equal number of new, equivalent orbitals suited to bonding.
Foundations of ChemistryHydrate
A crystalline compound in which a definite number of water molecules is incorporated into the lattice.
Inorganic & Coordination ChemistryHydrate Isomerism
Isomerism arising from water molecules occupying either the coordination sphere or lattice positions outside it.
Solutions & Colligative PropertiesHydration Energy
The energy released when one mole of gaseous ions is surrounded by water molecules to form a dilute aqueous solution.
Stoichiometry & Chemical ReactionsHydration Reaction
The addition of water across a multiple bond or the incorporation of water into a crystal lattice.
Organic ChemistryHydrocarbon
A compound composed exclusively of carbon and hydrogen.
Chemical Bonding & Molecular StructureHydrogen Bond
A strong dipole interaction between a hydrogen atom bonded to N, O or F and a lone pair on another such atom.
Electrochemistry & RedoxHydrogen–Oxygen Fuel Cell
A fuel cell in which hydrogen is oxidised at the anode and oxygen reduced at the cathode, producing only water.
Stoichiometry & Chemical ReactionsHydrolysis
A reaction in which a bond is cleaved by water, with the H and OH fragments adding to the two products.
Acids, Bases & SaltsHydrolysis Constant
The equilibrium constant for the hydrolysis of a salt ion in water.
Organic ChemistryHyperconjugation
The stabilising delocalisation of electrons from a sigma C–H bond into an adjacent empty or partly filled p orbital.
Solutions & Colligative PropertiesHypertonic Solution
A solution with a higher osmotic pressure than the one it is compared with, drawing water out of the more dilute side.
Solutions & Colligative PropertiesHypotonic Solution
A solution with a lower osmotic pressure than the one it is compared with, so water flows into the more concentrated side.
Organic ChemistryHückel's Rule
The rule that a planar cyclic conjugated system is aromatic if it contains 4n + 2 pi electrons.
Chemical EquilibriumICE Table
A systematic tabulation of Initial, Change and Equilibrium amounts used to solve equilibrium problems.