Browse All 960 Chemistry Terms A–Z

Degree of Hydrolysis Acids, Bases & Salts Dimensionless The fraction of a salt's ions that have reacted with water at equilibrium. h = √(Kh / c)

Degree of Ionisation Acids, Bases & Salts Dimensionless The fraction of dissolved electrolyte molecules that have broken into ions at equilibrium. α = ionised / total

Degree of Polymerisation Biochemistry & Polymer Chemistry Dimensionless The number of monomer units in an average polymer chain. DP = M_polymer / M_monomer

Dehydration Reaction Stoichiometry & Chemical Reactions Dimensionless A reaction in which water is removed from a single molecule, generally producing an unsaturated or condensed product. R–CH₂–CH₂OH → R–CH=CH₂ + H₂O

Deliquescence Foundations of Chemistry Dimensionless The property of a solid that absorbs enough water vapour from the air to dissolve completely in the water it takes up.

Delocalisation Chemical Bonding & Molecular Structure Dimensionless The spreading of electrons over three or more atoms rather than their confinement between two.

Denaturation Biochemistry & Polymer Chemistry Dimensionless The loss of a protein's native three-dimensional structure without breaking its peptide bonds.

Density Foundations of Chemistry g/cm³ The mass of a substance contained in a unit volume, a characteristic intensive property of each material. ρ = m / V

Denticity Inorganic & Coordination Chemistry Dimensionless The number of donor atoms a single ligand uses to bind to one metal centre. κⁿ or ηⁿ notation

Deposition States of Matter & Gas Laws kJ/mol The direct conversion of a vapour into a solid without an intermediate liquid phase.

Diagonal Relationship Atomic Structure & Periodicity Dimensionless The similarity in properties between an element of period 2 and the element one place to its lower right in period 3.

Diamagnetism Atomic Structure & Periodicity BM Weak repulsion from a magnetic field, shown by substances in which all electrons are spin-paired. μ = 0 BM

Diastereomer Organic Chemistry Dimensionless A stereoisomer that is not a mirror image of the compound with which it is compared.

Diffusion States of Matter & Gas Laws m²/s The spontaneous spreading of one substance through another as a result of random molecular motion. J = −D (dc/dx)

Dilution Solutions & Colligative Properties mol/L The process of reducing a solution's concentration by adding more solvent, leaving the amount of solute unchanged. M₁V₁ = M₂V₂

Dimensional Analysis Foundations of Chemistry Various A calculation method that tracks and cancels units through a chain of conversion factors to reach the required quantity. given quantity × (desired unit / given unit) = answer

Dipole Moment Chemical Bonding & Molecular Structure D The vector measure of the separation of positive and negative charge in a bond or molecule. μ = q × d

Dipole–Dipole Interaction Chemical Bonding & Molecular Structure kJ/mol The electrostatic attraction between the positive end of one polar molecule and the negative end of another. E ∝ μ₁μ₂ / r³

Diprotic Acid Acids, Bases & Salts mol/L An acid that can donate two protons per molecule. H₂A ⇌ 2H⁺ + A²⁻

Disaccharide Biochemistry & Polymer Chemistry Dimensionless A carbohydrate formed when two monosaccharide units join through a glycosidic bond. C₁₂H₂₂O₁₁

Disproportionation Reaction Stoichiometry & Chemical Reactions Dimensionless A redox reaction in which a single species is simultaneously oxidised and reduced. 2A → A⁺ + A⁻

Dissociation Solutions & Colligative Properties Dimensionless The breaking apart of a solute into two or more particles when it dissolves, increasing the effective particle count. AB → A⁺ + B⁻

Dissociation Constant Chemical Equilibrium mol/L The equilibrium constant for the breaking apart of a compound or complex into smaller species. Kd = [A][B] / [AB]

Dissolution Solutions & Colligative Properties kJ/mol The process by which a solute disperses into a solvent to form a solution.

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