Results for “pH”
35 terms · page 1 of 2
pH
The negative logarithm to base ten of the hydrogen ion concentration, measuring the acidity of a solution.
Acids, Bases & SaltspH Scale
The conventional scale, usually running from 0 to 14, on which the acidity or alkalinity of aqueous solutions is expressed.
States of Matter & Gas LawsPhase Diagram
A pressure–temperature plot showing which phase of a substance is thermodynamically stable under any given conditions.
Chemical EquilibriumPhase Equilibrium
The condition in which two or more phases of a substance coexist with no net transfer between them.
Organic ChemistryPhenol
A compound in which a hydroxyl group is bonded directly to an aromatic ring.
Acids, Bases & SaltsPhenolphthalein
An acid–base indicator that is colourless in acid and pink in alkaline solution, changing between pH 8.3 and 10.0.
Biochemistry & Polymer ChemistryPhospholipid
A lipid in which one fatty acid of a triglyceride is replaced by a phosphate-containing group.
Chemical Kinetics & CatalysisPhotochemical Quantum Yield
The number of molecules reacting for each photon of light absorbed by the system.
Stoichiometry & Chemical ReactionsPhotochemical Reaction
A reaction initiated by the absorption of light, which promotes a molecule to an electronically excited state.
Biochemistry & Polymer ChemistryPhotosynthesis
The process by which plants use light energy to convert carbon dioxide and water into carbohydrate and oxygen.
Foundations of ChemistryPhysical Change
A change that alters the form or state of a substance while leaving its chemical composition intact.
Chemical EquilibriumPhysical Equilibrium
An equilibrium between two physical states or phases of the same substance.
Foundations of ChemistryPhysical Property
A characteristic of a substance that can be observed or measured without altering its chemical identity.
Chemical Kinetics & CatalysisPhysisorption
Weak adsorption in which molecules are held to a surface by van der Waals forces alone.
States of Matter & Gas LawsPolymorphism
The ability of a single substance to exist in more than one crystalline form.
Chemical EquilibriumPartition Coefficient
The equilibrium ratio of a solute's concentrations in two immiscible phases.
Atomic Structure & PeriodicityPlum Pudding Model
J. J. Thomson's 1904 model picturing the atom as a sphere of diffuse positive charge with electrons embedded within it.
Foundations of ChemistryPure Substance
Matter with a fixed chemical composition and a definite set of physical properties, comprising either a single element or a single compound.
States of Matter & Gas LawsPacking Efficiency
The percentage of the total volume of a unit cell that is actually occupied by the constituent particles.
Solutions & Colligative PropertiesParts per Million
A concentration unit expressing one part of solute per million parts of solution by mass or volume.
Nuclear & RadiochemistryPenetrating Power
The depth to which a given type of radiation can travel into a material before being absorbed.
Stoichiometry & Chemical ReactionsPercentage Purity
The proportion of a sample that consists of the desired compound, expressed as a percentage of the total mass.
Stoichiometry & Chemical ReactionsPercentage Yield
The actual yield expressed as a percentage of the theoretical yield.
Acids, Bases & SaltspKa
The negative logarithm of the acid dissociation constant, giving a convenient scale of acid strength.