Acids, Bases & Salts n Acid Properties : n Sour taste, react with metals to produce hydrogen gas,...

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Acids, Bases & Salts Acids, Bases & Salts Acid Properties:

Sour taste, react with metals to produce hydrogen gas,

electrolytes, affect indicators (turns blue litmus paper to

red)

Acids, Bases & Salts Acids, Bases & Salts Base Properties: Bitter taste, produce

electrolytes, affect indicators (turns red litmus

paper to blue)

Acids Acids Electrolytes: substances

that conduct electric current when dissolved in

water.

Acids Acids Indicators: chemical substances that change

color based on acid concentration.

Acids Acids Arrhenius Theory: acids

produce H+ ions when dissolved (ionized) in

water.

Acids Acids Arrhenius Theory: bases

produce OH- ions when dissolved (ionized) in

water.

Acids Acids Dissociation vs. ionization: dissociation is the separation

of ions in solution. In ionization, neutral molecules react with water to form ions.

Acids Acids Bronsted-Lowry Theory:

acids donate protons (H+) in a chemical reaction.

Ex. HCl(g) + H2O(l) --> H3O+(aq) + Cl-(aq)

Acids Acids The HCl gas donates a

proton to the water molecule, producing the hydronium ion. HCl is considered an

acid, water is considered a base.

Acids Acids Bronsted-Lowry Theory: bases accept protons (H+) in

a chemical reaction.HCl and Cl- are considered

a conjugate acid/base pair.

Acids Acids Conjugate acid/base pairs:

Conjugate base - the particle leftover after the

acid donates a proton.

Acids Acids Conjugate acid/base pairs:

Conjugate acid - the particle produced after the

base accepts the proton.

Acids Acids Identify the acid, base,

conjugate base and conjugate acid in the following:

HNO3(aq) + NaOH(aq) --> H2O(l) + NaNO3(aq).

Acids Acids Practice problems #1-2, p.

576.What do you want to

know?

Acids Acids Lewis Theory: an acid is any

substance that accepts an electron pair. A base is any substance that donates an

electron pair. NH3 + BF3 --> NH3BF3

Acids Acids Use electron dot diagrams to determine if a substance

is a Lewis acid or base.Ex. Classify Cl- as a Lewis

acid or base.

Acids Acids Coordination complexes:

molecular ligands (attachments) approach a

metal cation and bond using secondary (d-orbital)

valance.

Acids Acids Complex ion formation: ex.

Ag+ + NH3 --> ? (coordination number of 2).

Acids Acids What is the name of

[CoCl2(NH3)5]Br

Practice Problems #3-8, p. 578. Any questions?

Acid Nomenclature Acid Nomenclature Binary acids: acids

consisting of 2 elements.Ex. HCl

HIHBr

Acid Nomenclature Acid Nomenclature Ternary Acids and Bases:

acids or bases containing three elements.

Common ternary acid - formed by using H+ and a common polyatomic ion.

Acid Nomenclature Acid Nomenclature Use the polyatomic name and

the suffix -ic. Ex. H2SO4

HNO3

HClO3

Acid Nomenclature Acid Nomenclature A ternary acid that is the same as the common acid but with one less oxygen uses the suffix -ous.

Ex. H2SO3

HClO2

Acid Nomenclature Acid Nomenclature A ternary acid that is the same as the common acid but with two less oxygens uses the prefix -hypo and the suffix -

ous. Ex. HClO

Acid Nomenclature Acid Nomenclature A ternary acid that is the same as the common acid but with one more oxygen uses the prefix -per and the suffix -ic.

Ex. HClO4

Acid Nomenclature Acid Nomenclature Common ternary base - formed by using metal and the hydroxide polyatomic

ion.Ex. NaOH, Mg(OH)2

Acid Nomenclature Acid Nomenclature Organic acids: carboxylic

acids, -COOHName the chain and add -

oic acid.

Acid Nomenclature Acid Nomenclature Practice Problems #9-13, p.

580Wha?

Acid/Base Behavior Acid/Base Behavior Consider a compound in the

form HOX. If X is very electronegative then the H is given up as a proton and it acts as an acid. If not it acts

as a base.

Acid/Base Behavior Acid/Base Behavior So, nonmetals tend to form

acids, metals tend to form bases when dissolved in water.

Ex. MgO CO

Acid/Base Behavior Acid/Base Behavior Acidic and Basic Anhydrides:

acids and bases that have had water removed.

Ex. Acid anhydride + water --> acid

Acid/Base Behavior Acid/Base Behavior Ex. Acid anhydride + water

--> acidSO2 + H2O --> H2SO3

Acid/Base Behavior Acid/Base Behavior Ex. basic anhydride +

water --> baseNa2O + H2O --> 2 NaOH

Practice problems #14-15 p. 583

Acid/Base Behavior Acid/Base Behavior Acid base strength: not all acids complete ionize in water.

That is a lot of the acid or base molecules remain

unreacted. Ex. Ammonia (weak base)

Acid/Base Behavior Acid/Base Behavior Concept review #16-19 p.

584

Salts and Solutions Salts and Solutions Salt : an ionic compound that

does not consist of H+ or OH-

Ex. KCl, MgO (any ionic compound that is not an Arrehnius acid or base)

Neutralization Neutralization Neutralization reaction: a

acid reacts with a base to produce a salt and water.

Really just a double displacement reaction

Neutralization Neutralization Ex. Produce the products

and balance the equation for the reaction of the acid HCl and the base AgOH.

Neutralization Neutralization Naming salts - who cares?

Ex. Sodium hydrogen carbonate

Ex. Sodium dihydrogen phosphate

Net Ionic EquationsNet Ionic EquationsSome ions in a

neutralization reaction are considered spectator ions.

That is, they are unchanged after the reaction.

Net Ionic EquationsNet Ionic EquationsChemists often write net

ionic equations to show only those ions that actually take place in the reaction.

Ex. HCl + NaOH

Net Ionic EquationsNet Ionic EquationsPolyprotic acids - go

through two steps of ionization

Ex. Sulfuric acid

Net Ionic EquationsNet Ionic Equations The binary acids HCl, HBr,

and HI are strong acids, the rest are weak.

Ternary acids with 2 or more oxygens versus hydrogens are

strong.

Net Ionic EquationsNet Ionic Equations Organic acids are weak.

Polyprotic acids: second step always results in a weak acid Group 1 and 2 bases are

strong.

Net Ionic EquationsNet Ionic Equations Molecules and weak acids and

bases are not written in ionic form.

Salts are written in ionic form, oxides and gases are written

as molecules.

Net Ionic EquationsNet Ionic EquationsPractice problems #23-27

p. 590. (in groups - 15 minutes)

Ionization ConstantIonization ConstantThe Keq for the ionization

of a weak acid or base determines the extent that

[H3O+] or [OH-] ions will be produced at equilibrium.

Ionization ConstantIonization ConstantKa is the ionization

constant of a weak acid. HX + H2O <--> H3O+ + X-.

What is Ka for this reaction?

Ionization ConstantIonization Constant Kb is the ionization constant of

a weak base. NH3 + H2O <--> NH4

+ + OH-.

What is Kb for this reaction?

Ionization ConstantIonization ConstantPercent ionization =

[amount ionized] / [original acid] x 100%

Problems 28-31, p. 592-593

Ionization ConstantIonization ConstantCommon Ion Effect - adding

ions that are the same as one of those produced by the

ionization of a weak electrolyte …. (more)

Ionization ConstantIonization Constant to a solution of the

electrolyte suppresses its ionization. Why???

Ionization ConstantIonization ConstantLe Chatelier’s Principle -

you are increasing the concentration of products.

The system responds to reestablish equilibrium.

Ionization ConstantIonization ConstantProblems 42-65 p. 597-598.