STRUCTURAL EFFECTS ON ACIDITY AND BASICITY

ACID

pH<7

ACID

Sour taste

ACID

Turns litmus paper to red

ACID

React with bases to

neutralize their properties

ACID AND BASE

Conducts electricity

BASE

pH>7

BASE

Bitter taste

BASE

Turns litmus paper to blue

BASE

React with acids to

neutralize their properties

Arrhenius Acids and Bases

concept is based on whether the substance yields H+ or OHin aqueous solutions.

acid

is a substance that, when dissolved in water, increases the concentration of

H+

ions.

base

is a substance that, when dissolved in water, increases the concentration of

OH- ions.

Arrhenius Acids and Bases Limitations

restricted to aqueous solutions

Arrhenius Acids and Bases

defined based on production of ions

Arrhenius Acids and Bases

it can’t exist when not dissolved in water

higher

Acid H+ ions have _ aq solns

Brønsted-Lowry Acids and Bases

concept is based on the fact that acid–base reactions involve the transfer of H+

ions/proton from one substance to another.

acid

is a substance (molecule or ion) that donates a proton to another substance;

proton donor.

base

is a substance that accepts a proton; proton acceptor.

proton

The transfer of a _ always involves both an acid (donor) and a base (acceptor).

Brønsted-Lowry Acids and Bases

Not limited to aqueous solutions.

Brønsted-Lowry

diff people and did not know eo but they discovered the same thing

Brønsted-Lowry Acids and Bases

can be in a gaseous form

# of electrons

H atom and H ions difference

mass #

number of protons and neutrons

base

acid cannot exist without

Conjugate Acid-Base Pairs

In any acid–base equilibrium, both the forward reaction (to the right) and the reverse

reaction (to the left) involve proton transfer.

conjugate base

Every acid has a _, formed by removing a proton from the acid.

◦ HA – A-

conjugate acid

Every base has a _, formed by adding a proton to the base.

◦ H2O – H3O+

NO2- (aq)

HNO2 acid to cb

H3O+ (aq)

H2O (l) base to ca

NH4+ (aq)

NH3 (aq) base to ca

OH- (aq)

H2O (l) acid to cb

H2O

may either be a proton acceptor or proton donor depending on the reaction (depends on its partner)

acid

base

conjugate acid

conjugate base

base

cb

ca

acid

Any species that has a hydrogen can potentially act as an _.

base

Any species that has a lone pair can potentially act as a _.

amphiprotic

A substance capable of acting as either an acid or a base is called _.

amphiprotic

An _ substance acts as a base when combined with something more strongly

acidic than itself and as an acid when combined with something more strongly basic

than itself.

Acidity

_ is a measure of the tendency of a compound to lose a proton, whereas basicity

is a measure of a compound’s affinity for a proton.

basicity

Acidity is a measure of the tendency of a compound to lose a proton, whereas _

is a measure of a compound’s affinity for a proton.

better or stronger

acid base ca cb depends on which is the _ acid or base depending on the rxn

acid

A strong _ has a strong tendency to lose a proton; thus, its conjugate base is weak

because it has little affinity for the proton.

conjugate base

A strong acid has a strong tendency to lose a proton; thus, its _ is weak because it has little affinity for the proton.

weak acid

A _ has little tendency to lose a proton; thus, its conjugate base is strong

because it has a high affinity for the proton.

conjugate base

A weak acid has little tendency to lose a proton; thus, its _ is strong because it has a high affinity for the proton.

stronger

The _ the acid, the weaker its conjugate base.

weaker

The stronger the acid, the _ its conjugate base.

ClO4-, HS-, PH3, CO32-

what is the cb of HClO4, H2S, PH4+, HCO3-?

HCN, HSO4-, H3O+, H2CO3

what is the ca of CN-, SO42-, H2O, HCO3-?

H2SO3, HF, HPO42-, HCO+

write the formula for the ca of each of the following:

HSO3-, F-, PO43-, CO

Ka and pKa

Acid and base strength are expressed in _ 2

HCl, HBr, HI, HNO3,

HClO3, and HClO4)

The most common strong acids include six monoprotic acids (_), and one diprotic acid (H2SO4).

H2SO4

◦ The most common strong acids include six monoprotic acids (HCl, HBr, HI, HNO3,

HClO3, and HClO4), and one diprotic acid (_).

strong acids

The most common _ include six monoprotic acids (HCl, HBr, HI, HNO3,

HClO3, and HClO4), and one diprotic acid (H2SO4).

HCl, HBr, HI, HNO3,

HClO3, and HClO4, and H2SO4

most common strong acids (7)

Strong bases and Strong acids

_ 2 ionize completely in water.

strong bases

The most common _ include hydroxides of the alkali metals (NaOH, KOH) and hydroxides of alkaline earth metals (Ca(OH)2, Sr(OH)2, and Ba(OH)2).

NaOH, KOH

The most common strong bases include hydroxides of the alkali metals (_ 2) and hydroxides of alkaline earth metals (Ca(OH)2, Sr(OH)2, and Ba(OH)2).

Ca(OH)2, Sr(OH)2, and Ba(OH)2

The most common strong bases include hydroxides of the alkali metals (NaOH, KOH) and hydroxides of alkaline earth metals (_ 3).

NaOH, KOH, and Ca(OH)2, Sr(OH)2, and Ba(OH)2

most common strong bases 5

Weak acids & Weak bases

_ 2 ionize partially in water.

strong acids

→

strong bases

→

weak acids

←→

weak bases

←→

Ka

(acid-dissociation constant)

The higher the Ka, the stronger the acid.

Ka

(acid-dissociation constant) for an acid HA is:

Kb

(base-dissociation constant)

The higher the Kb, the stronger the base.

Kb

(base-dissociation constant) for a base B is:

higher; stronger

The _ the Ka, the - the acid.

The _ the Kb, the - the base.

Ka formula

Kb formula

larger pKa

A stronger acid (larger Ka) has a smaller pKa, and a weaker acid (smaller Ka) has a _.

weaker acid (smaller Ka)

A stronger acid (larger Ka) has a smaller pKa, and a _ has a

larger pKa.

smaller pKa

A stronger acid (larger Ka) has a _, and a weaker acid (smaller Ka) has a

larger pKa.

stronger acid (larger Ka)

A _ has a smaller pKa, and a weaker acid (smaller Ka) has a

larger pKa.

pKa formula

very strong acids

pka <1

moderately strong acids

pKa=1-3

weak acids

pKa=3-5

very weak acids

pKa=5-15

extremely weak acids

pKa>15

weaker acid to stronger acid

CH3CH2OH to HCl

weaker base to stronger base

HCl to CH3CH2OH

smaller pKa

stronger acid (larger Ka) has a _

larger pKa

weaker acid (smaller Ka) has a_

1.0 x 10-14 at 25°C

(Ka)(Kb) = Kw =

14 at 25°C

pKa + pKb =

.

Ka increases Kb decreases and vice versa

pKa increases pKb decreases and vice versa

divide 1×10-14 by the Ka then u get Kb

Ka derive Kb

negative logarithm of ka

derive pKa from Ka

14-pka

derive pkb from pka