CHEM 122 Ch. 14.1-7

Characteristic property of acids

neutralize bases

Characteristic property of bases

neutralize acids

An arrhenius ____ increases the concentration of _______ ions in water.

acid, H₃O⁺ (hydronium)

An arrhenius ____ increases the concentration of _______ ions in water.

base, OH⁻ (hydroxide)

Bronsted-Lowry acid

donates H+

Bronsted-Lowry base

accepts H+

Lewis acid

accepts electron pair

Lewis base

donates electron pair

Conjugate base

what’s left after an acid loses H⁺

Conjugate acid

what forms after a base gains H⁺

An ________ substance is something that can act as either an acid or a base, depending on what it’s reacting with.

amphiprotic/amphoteric

The reaction between a Brønsted-Lowry acid and water is called

acid ionization

____________ of a species occurs when it accepts protons from water molecules.

Base ionization

K_w

ion-product constant for water

The extent of the water __________ process is reflected in the value of its equilibrium constant, K_w.

autoionization

The autoionization of water yields the _____ number of hydronium and hydroxide ions.

same

A solution is _____ if it contains equal concentrations of hydronium and hydroxide ions; _____ if it contains a greater concentration of hydronium ions than hydroxide ions; and _____ if it contains a lesser concentration of hydronium ions than hydroxide ions.

neutral, acidic, basic

pH =

−log⁢[H3⁢O+]

[H3⁢O+]=

10⁻ᵖᴴ

pOH =

−log⁢[OH−]

[OH−] =

10⁻ᵖᴼᴴ

pH + pOH =

14

Acidic solutions at 25 degrees C have a pH ___ 7.

<

Basic solutions at 25 degrees C have a pH ___ 7.

>

Neutral solutions at 25 degrees C have a pH ___ 7.

=

The equilibrium constant for an acid is called the

acid-ionization constant (Ka)

An acid is classified as _____ when it undergoes complete ionization, in which case the concentration of HA is zero and the acid ionization constant is immeasurably large (Ka ≈ ∞).

strong

Percent ionization of a weak acid =

equilibrium hydronium concentration divided by initial acid concentration, times 100.

% ionization =

([H₃O⁺]eq / [HA]₀) × 100

____ Ka = _____ acid

bigger, stronger

The more _____ a molecule or ion is, the less _____ it is.

acidic, basic

The stronger the ____, the weaker is the conjugate ___.

acid/base, base/acid.

Write the expression for the water dissociation equilibrium constant, Kw, and give its

numerical value at 25°C.

Kw = 1.00 x 10^-14 = [H30+][OH-]

The symbol "__" indicates the negative of the logarithm of a number.

p

You can only write Ka/b for ____ acids/bases.

weak

% ionization formula

[concentration of conjugate base at equilibrium] / [initial concentration of acid] x 100

Strong acids/bases are 100% ________.

ionized/dissociated

When comparing acids in the same row of the periodic table, the acid with X furthest to the ____ is strongest.

right

When comparing acids in the same column of the periodic table, the acid with X ____ on the periodic table is strongest.

lower

Acid strength increases across a period because ____ increases.

EN

Acid strength increases down a group because X gets ______, making H ______ to break off.

bigger, easier

Acid strength is determined by how easily it _______.

ionizes

Oxoacids contain

O, H, and a central, nonmetal atom

For oxyacids with the same central atom, acid strength ______ as the # of oxygen atoms attached to central atom ______ (draws e- away from H-O bond)

increases, increases

For oxyacids with different central atoms, acid strength _______ as you go ___ a group because of increasing EN (draws e- away from H-O bond)

increases, up/right

For oxyacids, acid strength ______ as the negative charge of the species ______.

decreases, increases

Oxyacid strength priority

More O atoms attached to the central atom → stronger acid; if the number of O atoms is the same, a more electronegative central atom → stronger acid; a more negative charge → weaker acid.

______ is the strongest acid that can exist in water.

Hydronium (H3O+)

_______ is the strongest base that can exist in water.

Hydroxide (OH-)

______ Ka = ______ acid

bigger, stronger