- 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 (Ka)
- 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 (Kb)
- 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 (Kw)
- 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