Search results for “Mole”

Physical Change Foundations of Chemistry Dimensionless A change that alters the form or state of a substance while leaving its chemical composition intact.

Pi Bond Chemical Bonding & Molecular Structure kJ/mol A covalent bond formed by the sideways overlap of parallel p orbitals, with electron density above and below the internuclear axis.

pKa Acids, Bases & Salts Dimensionless The negative logarithm of the acid dissociation constant, giving a convenient scale of acid strength. pKa = −log Ka

Polar Covalent Bond Chemical Bonding & Molecular Structure D A covalent bond in which the shared electrons are unequally distributed because the bonded atoms differ in electronegativity. δ⁺A—Bδ⁻

Positive Deviation Solutions & Colligative Properties Pa Behaviour in which a solution exerts a higher vapour pressure than Raoult's law predicts. p > x p°

Pyrolysis Stoichiometry & Chemical Reactions °C The thermal decomposition of a substance at high temperature in the absence of oxygen. complex → simpler fragments (Δ, no O₂)

Racemic Mixture Organic Chemistry degrees An equimolar mixture of two enantiomers, which shows no net optical rotation. 50:50 (+) and (−)

Radiopharmaceutical Nuclear & Radiochemistry MBq A radioactive compound administered to a patient for diagnosis or treatment.

Relationship between Kp and Kc Chemical Equilibrium Dimensionless The conversion linking the pressure and concentration forms of the equilibrium constant for a gaseous reaction. Kp = Kc(RT)^Δn

Relative Lowering of Vapour Pressure Solutions & Colligative Properties Dimensionless The fractional reduction in a solvent's vapour pressure caused by dissolving a non-volatile solute. (p° − p) / p° = x_solute

RNA Biochemistry & Polymer Chemistry Dimensionless A generally single-stranded nucleic acid that carries out the expression of genetic information.

Saturation and Unsaturation Organic Chemistry Dimensionless The distinction between compounds containing only single bonds and those containing multiple bonds or rings. DoU = (2C + 2 + N − H − X)/2

Schrödinger Wave Equation Atomic Structure & Periodicity J The fundamental equation of quantum mechanics whose solutions give the allowed energies and wavefunctions of a system. Ĥψ = Eψ

Second-Order Reaction Chemical Kinetics & Catalysis L/(mol·s) A reaction whose rate depends on the square of one concentration or on the product of two concentrations. 1/[A] = 1/[A]₀ + kt

Secondary Valence Inorganic & Coordination Chemistry Dimensionless In Werner's theory, the non-ionisable valence corresponding to the coordination number, satisfied by ligands in fixed spatial positions.

Selectivity Chemical Kinetics & Catalysis Dimensionless The ability of a catalyst to direct a reaction towards one particular product among several possible ones. selectivity = desired product / total product

SI Base Units Foundations of Chemistry Various The seven defined units of the International System from which every other measurement unit is derived.

Solid State States of Matter & Gas Laws Dimensionless The state of matter in which particles are held in fixed positions, giving a definite shape and volume.

Solubility of Gases Solutions & Colligative Properties mol/L The amount of a gas that dissolves in a given volume of liquid at a stated temperature and partial pressure. S ∝ p, S decreases with T

Solvent Solutions & Colligative Properties L The component of a solution present in the greater amount, which dissolves and disperses the solute.

Specific Heat Capacity Thermochemistry & Thermodynamics J/(kg·K) The heat required to raise the temperature of one kilogram of a substance by one kelvin. c = q / (mΔT)

sp³ Hybridisation Chemical Bonding & Molecular Structure degrees The mixing of one s and three p orbitals to give four hybrid orbitals directed towards the corners of a tetrahedron. 4 hybrids, 109.5°

Steric Factor Chemical Kinetics & Catalysis Dimensionless The fraction of sufficiently energetic collisions that also have the correct spatial orientation for reaction. p = A / Z

Stoichiometric Coefficient Stoichiometry & Chemical Reactions Dimensionless The number written before a formula in a balanced equation, giving the relative amount of that substance consumed or produced.

Results for “Mole”