Term | Definition |
acidic solution | A solution with more H 3 O+ ions than OH- ions, resulting in a pH less than 7. |
acid-ionization constant | Related to the ionization constant of water, it is the value that describes the extent of the forward equilibrium reaction in the formation of the hydronium ion. |
amphoteric | A substance that can act as either a Bronsted-Lowry acid or base. |
Arrhenius acid | A substance that releases hydrogen ions (H+) when dissolved in water. |
Arrhenius base | A substance that releases hydroxide ions (OH-) when dissolved in water. |
base-ionization constant | Related to the ionization constant of water, the value that describes the extent of the forward equilibrium reaction in the formation of the hydroxide ion. |
basic solution | A solution with fewer H 3 O+ ions than OH- ions, resulting in a pH greater than 7; also called an alkaline solution. |
Bronsted-Lowry acid | A substance that donates protons. |
Bronsted-Lowry base | A substance that accepts protons. |
buffer | A solution that resists changes in pH when a moderate amount of either an acid or base is added. |
conjugate acid | The structure formed when a base is protonated. |
conjugate base | The structure formed when an acid has donated a proton. |
conjugate pair | Two particles that differ from each other by only a proton (a hydrogen ion). |
deprotonation | The process of losing a proton. |
diprotic | An acid that can donate two protons. |
electrolyte | A substance that releases ions and conducts electricity when it dissolves in water. |
end point | The point in a titration at which some change in a property of the solution is detected. |
equivalence point | The point in a titration at which an equivalent amount of titrant has been added. The number of H 3 O+ ions equals the number of OH- ions. |
indicator | A substance that changes color when the pH of a solution changes. |
ionization constant of water | In self-ionization, the product of the concentrations of the hydronium ion (H 3 O+) and the hydroxide ion (OH-); 1.0 x 10 -14 at 25 °C; also called the dissociation constant of water. |
Lewis acid | Any substance that can accept a pair of electrons. |
Lewis base | Any substance that can donate a pair of electrons. |
monoprotic | An acid that can donate only one proton. |
neutralization reaction | The reaction of an acid and a base to produce a neutral solution (pH=7) of water and a salt. |
neutral solution | A solution with equal numbers of H 3 O+ and OH- ions; pH=7. |
pH | A measure of the hydronium ion (H 3 O+) concentration. It is the negative logarithm of the molar H 3 O+ ion concentration:
pH=-log (H 3 O+). |
pOH | A measure of the hydroxide ion (OH-) concentration. It is the negative logarithm of the molar OH- ion concentration:
pOH=-log (OH-). |
polyprotic | An acid that can donate more than one proton per molecule. |
protonation | The process of gaining a proton. |
salt | An ionic compound formed from the cation of a base and the anion of an acid. |
self-ionization of water | A process in an acid-base reaction in which one molecule donates a proton to another molecule of the same substance; also called auto-ionization or autoprotolysis. |
strong acid | A substance that readily gives up protons and ionizes completely in an aqueous solution. |
strong base | A substance that readily accepts protons. |
titration | A controlled reaction (often neutralization) conducted to measure the capacity of a solution of unknown concentration to react with one of known concentration. |
titration curve | A graph that plots the pH change of a solution versus the volume of added acids or bases. |
transition interval | An indicator's range of pH values over which a color change occurs. |
triprotic | An acid that can donate three protons. |
weak acid | A substance that does not give up protons easily and does not ionize completely in an aqueous solution; a weak electrolyte. |
week base | A substance that is a poor proton acceptor and does not ionize completely in an aqueous solution; a weak electrolyte. |