Acids and Bases

Vocabulary

Arrhenius acid

substance that releases hydrogen (H+) ions when dissolved in water

Arrhenius base

substance that releases hydroxide (OH) ions when dissolved in water

Brønsted-Lowry acid

compound that can donate a proton to another compound in solution

Brønsted-Lowry base

compound that can accept a proton from another compound in solution

carbanion

negatively charged carbon with three bonds and one lone pair of electrons

carbocation

positively charged carbon with three bonds and no lone pairs of electrons

conjugate acid

molecule or ion formed when a Brønsted-Lowry base has accepted a proton

conjugate base

molecule or ion remaining after a Brønsted-Lowry acid donates its proton to another molecule or ion

electron-pair acceptor

substance that can accept a pair of nonbonding electrons

electron-pair donor

substance that can donate a pair of nonbonding electrons

electronegativity

tendency of an atom to attract electrons toward itself when forming bonds

electrophile

molecule or ion that accepts electrons to form a covalent bond

equilibrium

state in which the rates of the forward and reverse reactions are equal

hybrid orbital

electron orbital that forms when two atomic orbitals combine to form a covalent bond

Lewis acid

electron-pair acceptor in a Lewis acid-base reaction

Lewis base

electron-pair donor in a Lewis acid-base reaction

molecular structure

three-dimensional shape of a molecule that takes into account bonding and nonbonding electron pairs, as well as molecular rotations to minimize their interactions

nucleophile

molecule or ion rich in electrons that donates a pair of electrons that forms a covalent bond

orbital

region in which an electron has a high probability of being located. Orbitals are described by the quantum numbers s, p, d, and f, which differ from one another by their shapes.

pKa

negative log of Ka, where Ka is the acid dissociation constant

potential energy

energy of an object based on its position

proton

H+ ion

proton acceptor

compound capable of removing a proton from another compound or solvent molecule

proton donor

compound that gives up a proton to another compound or solvent molecule

resonance

method that organic chemists use to deal with organic molecules that have two or more Lewis structures with multiple equivalent representations

resonance structure

one of two or more Lewis structures with multiple equivalent representations

strong acid

acid that completely dissociates and has a pH close to the low end of the spectrum. Strong acids have a large Ka.

strong base

base that completely dissociates and has a pH close to the high end of the spectrum. Strong bases have a large Kb.

weak acid

acid in which only a fraction of the molecules dissociates when dissolved in water, resulting in a low concentration of H+ and a pH closer to the middle of the range

weak base

base in which only a fraction of the molecules deprotonates in water, resulting in a low concentration of OH ions and a pH closer to the middle of the range