Bronsted - Lowry Acids and Bases

proton donor

protonacceptor

(they actually didn't work together)* Explains how acids and bases can work without the presence of water

An acid-base reaction is a proton transfer reaction.

CH3COOH + NH3

Conjugate Acid-Base Pair: a pair of molecules or ions that are related to one another by the gain or loss of a proton

Acids form conjugate basesBases form conjugate acids

1. Acids can be +, neutral or -2. Bases can be neutral or -3. Acids can be monoprotic, diprotic or triprotic.4. Amphiprotic5. In some cases, not all H's are given up:

acetic acidphenol

6. Inverse relationship b/w strength of acid and its conjugate base.

Determining Equilibrium Position

Strong acids:

HCl + H2O Cl- + H3O+

Weak acids:

CH3COOH + H2O CH3COO- + H3O+

CH3COOH + NH3 CH3COO- + NH4+?

CH3COOH + NH3 CH3COO- + NH4+?

1. Identify the acids.

acid acid

CH3COOH + NH3 CH3COO- + NH4+?

1. Identify the acids.

acidacid

2. Determine which acid is stronger:

CH3COOH + NH3 CH3COO- + NH4+?

1. Identify the acids.

acidacid

2. Determine which acid is stronger.3. Do the same with the bases (Identify the stronger and weaker bases)

basebase

CH3COOH + NH3 CH3COO- + NH4+

acidacid

basebase

1. Identify the acids.2. Determine which acid is stronger.3. Identify the stronger and weaker bases:4. Stronger always react to give weaker:

H3O+ + I- H2O + HICH3COO- + H2S CH3COOH + HS-

How do we use IONIZATION CONSTANTS?

an equilibrium constant for weak acids or weak bases

All ionizations of weak acids or bases in water are at equilibrium.We use equilibrium constants to quantitatively show how strong a weak acid or base is.

HA + H2O A- + H3O+

K = [A-][H3O+][HA][H2O]

Ka = K[H2O] =[A-][H3O+]

[HA]

because water is the solvent and []changes VERY little when HA is added,we combine it with K to give a new constant

ACID IONIZATION CONSTANT

Properties of acids and bases:1. Neutralization

a) Reaction with metal hydroxides

b) Reaction with Metal oxides:

c) Reaction with Carbonates and bicarbonates

HCl + CaCO3

DOUBLEDISPLACEMENT

NaHCO3

(a basic salt)

react with vinegar to get pocketsof CO2 in batter

(yogurt, chocolate, buttermilk)

leavening agents

cream of tartarNaHCO3

andpotassium hydrogen tartrate = weak acid)

2. Reaction with metalsSINGLE DISPLACEMENT

3. Reaction with ammonia and amines

HCl + NH3

HCl + CH3-NH2

Cl - H

p271: 24, 25, 27-29, 60, 61, 64, 68