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Chemistry: Atoms First 2e

Key Terms

Chemistry: Atoms First 2eKey Terms

acid ionization: reaction involving the transfer of a proton from an acid to water, yielding hydronium ions and the conjugate base of the acid

acid ionization constant (K_a): equilibrium constant for an acid ionization reaction

acid-base indicator: weak acid or base whose conjugate partner imparts a different solution color; used in visual assessments of solution pH

acidic: a solution in which [H₃O⁺] > [OH⁻]

amphiprotic: species that may either donate or accept a proton in a Bronsted-Lowry acid-base reaction

amphoteric: species that can act as either an acid or a base

autoionization: reaction between identical species yielding ionic products; for water, this reaction involves transfer of protons to yield hydronium and hydroxide ions

base ionization: reaction involving the transfer of a proton from water to a base, yielding hydroxide ions and the conjugate acid of the base

base ionization constant (K_b): equilibrium constant for a base ionization reaction

basic: a solution in which [H₃O⁺] < [OH⁻]

Brønsted-Lowry acid: proton donor

Brønsted-Lowry base: proton acceptor

buffer: mixture of appreciable amounts of a weak acid-base pair the pH of a buffer resists change when small amounts of acid or base are added

buffer capacity: amount of an acid or base that can be added to a volume of a buffer solution before its pH changes significantly (usually by one pH unit)

color-change interval: range in pH over which the color change of an indicator is observed

conjugate acid: substance formed when a base gains a proton

conjugate base: substance formed when an acid loses a proton

diprotic acid: acid containing two ionizable hydrogen atoms per molecule

diprotic base: base capable of accepting two protons

Henderson-Hasselbalch equation: logarithmic version of the acid ionization constant expression, conveniently formatted for calculating the pH of buffer solutions

ion-product constant for water (K_w): equilibrium constant for the autoionization of water

leveling effect: observation that acid-base strength of solutes in a given solvent is limited to that of the solvent’s characteristic acid and base species (in water, hydronium and hydroxide ions, respectively)

monoprotic acid: acid containing one ionizable hydrogen atom per molecule

neutral: describes a solution in which [H₃O⁺] = [OH⁻]

oxyacid: ternary compound with acidic properties, molecules of which contain a central nonmetallic atom bonded to one or more O atoms, at least one of which is bonded to an ionizable H atom

percent ionization: ratio of the concentration of ionized acid to initial acid concentration expressed as a percentage

pH: logarithmic measure of the concentration of hydronium ions in a solution

pOH: logarithmic measure of the concentration of hydroxide ions in a solution

stepwise ionization: process in which a polyprotic acid is ionized by losing protons sequentially

titration curve: plot of some sample property (such as pH) versus volume of added titrant

triprotic acid: acid that contains three ionizable hydrogen atoms per molecule

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- Authors: Paul Flowers, Edward J. Neth, William R. Robinson, PhD, Klaus Theopold, Richard Langley
- Publisher/website: OpenStax
- Book title: Chemistry: Atoms First 2e
- Publication date: Feb 14, 2019
- Location: Houston, Texas
- Book URL: https://openstax.org/books/chemistry-atoms-first-2e/pages/1-introduction
- Section URL: https://openstax.org/books/chemistry-atoms-first-2e/pages/14-key-terms

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