Chemistry - Unit 5

Bronsted-Lowry acid-base definition

A chemical species that donates a proton (hydrogen ion, H+) to another chemical species is called an acid, and a chemical species that accepts a proton is a base; the transfer of a proton from a proton donor (acid) to a proton acceptor (base)

Conjugate base

Chemical species that remains after an acid has donated a proton

Conjugate acid

Chemical species that forms after a base accepts a proton

Lewis acid-base definition

An acid is a chemical species that can accept a pair of electrons, and a base is a chemical species that can donate a pair of electrons

Autoionization

Type of reaction in which a substance ionizes when one molecule of the substance reacts with another molecule of the same substance

Amphiprotic

A molecule that can either gain a proton or lose a proton in a bronsted-lowry acid-base reaction

Amphoteric

A species that may act as either an acid or base by any definition

A larger Ka value corresponds to a…

Stronger acid (dissociates to a greater extent)

A smaller Ka value corresponds to a…

Weaker acid

A larger Kb corresponds to a…

Stronger base

A strong acid is (stronger/weaker) than H3O+

Stronger

A weak acid is (stronger/weaker) than H3O+

Weaker

A solution is neutral if [H3O+] (</>/=) [OH-]

=

A solution is acidic if [H3O+] (</>/=) [OH-]

>

A solution is basic if [H3O+] (</>/=) [OH-]

<

Carboxylic acid (a functional group) exhibits (acidic/basic) behavior in aqueous environments

acidic

An equilibrium favors the thermodynamically _____ energy (more stable) side of the reaction, and the magnitude of the equilibrium constant reflects the energy difference (G) between reactants and products

lower

Inductive effect

the pulling or pushing of electron density through sigma bonds due to electronegativity differences; electronegative atoms withdraw electron density, stabilizing nearby negative charge. The effect decreases with distance, and e- withdrawing groups increase acidity by stabilizing the conjugate base

Oxoacids

general formula: H(m)XO(n) [m = 1-3; n = 1-4]; acidity depends strongly on the number of terminal oxygen atoms (O atoms only bonded to central atom X); adding terminal O atoms causes strong inductive effect, thereby increasing the strength of the acid; electronegativity of the central atom also increases, which further enhances the inductive effect

Monoprotic acids

acids that contain one ionizable hydrogen atoms per molecule

Monoprotic base

bases that can accept a single proton

Dicarboxylic acids

group of commonly occuring diprotic acids

Charge density

the degree to which ion charge is concentrated in a given area or volume