Search results for “pH”

Electrophilic Addition Organic Chemistry Dimensionless A reaction in which an electrophile adds across a carbon–carbon multiple bond, converting a pi bond into two sigma bonds. C=C + E–Nu → C(E)–C(Nu)

Electrophilic Substitution Organic Chemistry Dimensionless A reaction in which an electrophile replaces a hydrogen atom on an aromatic ring. ArH + E⁺ → ArE + H⁺

Electrophoresis Analytical Chemistry & Spectroscopy cm/s A separation technique in which charged species migrate through a medium under an applied electric field. v = μE

Gas Chromatography Analytical Chemistry & Spectroscopy min A technique for separating volatile compounds carried by an inert gas through a heated column.

Gas Chromatography–Mass Spectrometry Analytical Chemistry & Spectroscopy Dimensionless A hybrid technique in which compounds separated by gas chromatography are identified by a mass spectrometer.

High-Performance Liquid Chromatography Analytical Chemistry & Spectroscopy min A technique in which a liquid mobile phase is pumped at high pressure through a column of very fine stationary phase.

Isomorphism States of Matter & Gas Laws Dimensionless The property of two or more different substances crystallising in the same structural form.

Mobile Phase Analytical Chemistry & Spectroscopy mL/min The fluid that carries the sample through the stationary phase during chromatography.

Nucleophile Organic Chemistry Dimensionless An electron-rich species that donates a pair of electrons to form a new covalent bond. Nu⁻ or Nu:

Nucleophilic Substitution Organic Chemistry Dimensionless A reaction in which a nucleophile replaces a leaving group attached to a saturated carbon. Nu⁻ + R–X → R–Nu + X⁻

Polymorphism States of Matter & Gas Laws Dimensionless The ability of a single substance to exist in more than one crystalline form.

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

Stationary Phase Analytical Chemistry & Spectroscopy Dimensionless The fixed material in a chromatographic system with which the sample components interact as they pass.

Thin Layer Chromatography Analytical Chemistry & Spectroscopy Dimensionless A chromatographic technique using a thin layer of adsorbent coated on a flat plate.

X-ray Crystallography Analytical Chemistry & Spectroscopy pm A technique that determines the three-dimensional atomic structure of a crystal from its X-ray diffraction pattern. nλ = 2d sin θ

Acidic Buffer Acids, Bases & Salts Dimensionless A buffer made from a weak acid and one of its salts, giving a pH below 7. pH = pKa + log([salt]/[acid])

Acidic Salt Acids, Bases & Salts Dimensionless A salt whose aqueous solution has a pH below 7, or one that still contains replaceable hydrogen.

Acid–Base Titration Acids, Bases & Salts mol/L A titration in which an acid is neutralised by a base, or the reverse, monitored by an indicator or a pH meter. M_aV_a / n_a = M_bV_b / n_b

Allotropy Foundations of Chemistry Dimensionless The existence of an element in two or more distinct structural forms within the same physical state.

Anisotropy States of Matter & Gas Laws Dimensionless The dependence of a physical property on the direction in which it is measured.

Basic Buffer Acids, Bases & Salts Dimensionless A buffer made from a weak base and one of its salts, giving a pH above 7. pOH = pKb + log([salt]/[base])

Basic Salt Acids, Bases & Salts Dimensionless A salt whose aqueous solution has a pH above 7, or one that retains a hydroxide group.

Bond Dissociation Enthalpy Thermochemistry & Thermodynamics kJ/mol The enthalpy change when one mole of a specific bond is broken homolytically in the gas phase. A–B(g) → A·(g) + B·(g)

Buffer Capacity Acids, Bases & Salts mol/L The amount of strong acid or base a buffer can absorb before its pH changes appreciably. β = dn / d(pH)

Results for “pH”