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960 terms · page 36 of 40
Spectator Ion
An ion present in a reaction mixture that undergoes no chemical change and appears identically on both sides of the equation.
Inorganic & Coordination ChemistrySpectrochemical Series
A ranking of ligands by the magnitude of the crystal field splitting they produce.
Atomic Structure & PeriodicitySpin Quantum Number
The quantum number mₛ describing the intrinsic angular momentum of an electron, restricted to +½ or −½.
Analytical Chemistry & SpectroscopySpin–Spin Coupling
The splitting of an NMR signal into multiple lines caused by interaction with neighbouring non-equivalent nuclei.
Thermochemistry & ThermodynamicsSpontaneity
The tendency of a process to occur without any continuous external input of energy.
Chemical Bonding & Molecular Structuresp² Hybridisation
The mixing of one s and two p orbitals to give three hybrid orbitals in a plane at 120° to each other.
Chemical Bonding & Molecular Structuresp³ Hybridisation
The mixing of one s and three p orbitals to give four hybrid orbitals directed towards the corners of a tetrahedron.
Chemical Bonding & Molecular Structuresp³d and sp³d² Hybridisation
Hybridisation schemes involving d orbitals that give five trigonal bipyramidal or six octahedral hybrid orbitals.
Inorganic & Coordination ChemistrySquare Planar Complex
A four-coordinate complex in which the ligands occupy the corners of a square around the metal.
Chemical EquilibriumStability Constant
The equilibrium constant for the formation of a complex ion from its metal ion and ligands.
Inorganic & Coordination ChemistryStability of Complexes
The thermodynamic tendency of a complex to persist rather than dissociate into metal ion and free ligands.
Analytical Chemistry & SpectroscopyStandard Deviation
A statistical measure of the spread of a set of repeated measurements about their mean.
Electrochemistry & RedoxStandard Electrode Potential
The potential of a half-cell measured against the standard hydrogen electrode under standard conditions.
Thermochemistry & ThermodynamicsStandard Enthalpy of Combustion
The enthalpy change when one mole of a substance burns completely in excess oxygen under standard conditions.
Thermochemistry & ThermodynamicsStandard Enthalpy of Formation
The enthalpy change when one mole of a compound forms from its elements in their standard states.
Electrochemistry & RedoxStandard Hydrogen Electrode
The reference half-cell, consisting of hydrogen gas at 1 bar bubbled over platinum in 1 M acid, assigned a potential of exactly zero.
Thermochemistry & ThermodynamicsStandard Molar Entropy
The absolute entropy of one mole of a substance in its standard state at 298 K.
Thermochemistry & ThermodynamicsStandard State
The reference condition of a pure substance at 1 bar pressure and a stated temperature, conventionally 298.15 K.
Foundations of ChemistryStandard Temperature and Pressure
A defined reference condition used to report and compare gas measurements, currently 0 °C and 100 kPa under IUPAC.
Analytical Chemistry & SpectroscopyStandardisation
The determination of the exact concentration of a solution by titrating it against a primary standard.
Biochemistry & Polymer ChemistryStarch
The storage polysaccharide of plants, consisting of amylose and amylopectin.
Thermochemistry & ThermodynamicsState Function
A property whose value depends only on the current state of the system, not on how that state was reached.
Chemical EquilibriumStatic Equilibrium
A state of no change in which the opposing processes have genuinely ceased rather than balancing.
Analytical Chemistry & SpectroscopyStationary Phase
The fixed material in a chromatographic system with which the sample components interact as they pass.