Chapter 6 chemistry

Acids:

Acids are part of the ionic world.

• They XX when they XX in water.

• The molecules are XX XX by their attraction for

the water.

• When acids ionize, they form X cations and anions.

• Acids that ionize virtually 100% are called

XX XX .

HCl + H2O (l) ® H3O+(aq) + Cl−(aq)

• Acids that only ionize a small percentage are called

XX XX

HF + H2O (l) H3O+(aq) + F−(aq)

Acids are part of the ionic world.

• They ionize when they dissolve in water.

• The molecules are pulled apart by their attraction for

the water.

• When acids ionize, they form H+ cations and anions.

• Acids that ionize virtually 100% are called

strong acids.

HCl + H2O (l) ® H3O+(aq) + Cl−(aq)

• Acids that only ionize a small percentage are called

weak acids.

HF + H2O (l) H3O+(aq) + F−(aq)

You need to KNOW the names and formulas of

these:

• Common Strong Acids

XX XX XX

XX XX XX

XX XX XX

XX XX XX

XX XX XX

XX XX XX

• Common Weak Acids

XX XX XX

XX XX XX

XX XX XX

XX XX XX

(or XX)

You need to KNOW the names and formulas of

these:

• Common Strong Acids

HCl hydrochloric acid

HBr hydrobromic acid

HI hydroiodic acid

HNO3 nitric acid

H2SO4 sulfuric acid

HClO4 perchloric acid

• Common Weak Acids

HF hydrofluoric acid

H3PO4 phosphoric acid

H2CO3 carbonic acid

CH3COOH acetic acid

(or HC2H3O2)

Bases:

Bases form XX ions in water.

- Strong bases: dissociation is 100%

KOH (aq) à K+ + OH-

- Weak bases: formation of OH- is not 100%

NH3 + H2O (l) à NH4+ (aq) + OH- (aq)

Bases form OH– ions in water.

- Strong bases: dissociation is 100%

KOH (aq) à K+ + OH-

- Weak bases: formation of OH- is not 100%

NH3 + H2O (l) à NH4+ (aq) + OH- (aq)

You need to KNOW the names and formulas of

these:

• Common Strong Bases

XX XX XX

XX XX XX

XX XX XX

XX XX XX

XX XX XX

XX XX XX

XX XX XX

XX XX XX XX

• Common Weak Bases

XX XX

You need to KNOW the names and formulas of

these:

• Common Strong Bases

LiOH lithium hydroxide

NaOH sodium hydroxide

KOH potassium hydroxide

RbOH rubidium hydroxide

CsOH cesium hydroxide

Ca(OH)2 calcium hydroxide

Sr(OH)2 strontium hydroxide

Ba(OH)2 barium hydroxide

• Common Weak Bases

NH3 ammonia

1. Strong electrolytes — completely separate into XX

Example: NaCl (table salt)

NaCl(s) → XX (aq) + XX(aq)

• 100% separates into XX

• Conducts XX well.

• Most soluble ionic compounds are XX XX

2. Nonelectrolytes — do NOT form XX

Example: Sugar (C₆H₁₂O₆)

C₆H₁₂O₆(s) → C₆H₁₂O₆(aq)

• Sugar XX but stays as whole molecules.

• No XX are formed.

• Does XX conduct electricity.

3. Acids — can be XX or XX electrolytes

Strong acid (HCl):

HCl(aq) → X (aq) + XX(aq)

• Almost 100% forms ions.

• Strong electrolyte.

• Single arrow (→).

Weak acid (HF):

HF(aq) ⇌ H⁺(aq) + F⁻(aq)

• Only partially forms ions.

• Weak electrolyte.

• Double arrows (⇌).

Easy way to remember

• Strong electrolyte: Lots of ions.

• Weak electrolyte: XX XX

• 
  

• Nonelectrolyte: XX XX

Dissociation = existing ions separate.

Ionization = molecules form ions

1. Strong electrolytes — completely separate into ions

Example: NaCl (table salt)

NaCl(s) → Na⁺(aq) + Cl⁻(aq)

• 100% separates into ions.

• Conducts electricity well.

• Most soluble ionic compounds are strong electrolytes.

2. Nonelectrolytes — do NOT form ions

Example: Sugar (C₆H₁₂O₆)

C₆H₁₂O₆(s) → C₆H₁₂O₆(aq)

• Sugar dissolves but stays as whole molecules.

• No ions are formed.

• Does NOT conduct electricity.

3. Acids — can be strong or weak electrolytes

Strong acid (HCl):

HCl(aq) → H⁺(aq) + Cl⁻(aq)

• Almost 100% forms ions.

• Strong electrolyte.

• Single arrow (→).

Weak acid (HF):

HF(aq) ⇌ H⁺(aq) + F⁻(aq)

• Only partially forms ions.

• Weak electrolyte.

• Double arrows (⇌).

Easy way to remember

• Strong electrolyte: Lots of ions.

• Weak electrolyte: Few ions.

• Nonelectrolyte: No ions.

Dissociation = existing ions separate.

Ionization = molecules form ions

Major Classes of Chemical Reactions

Double Displacement (Metathesis Reaction )

- XX XX

- XX XX reaction (XX XX)

- XX XX reaction

• Oxidation-Reduction reaction (Redox)

- XX XX

- XX XX

- XX XX reaction

- XX of substances in XX

Major Classes of Chemical Reactions

• Double Displacement (Metathesis Reaction )

- Precipitation reaction

- Acid-base reaction (neutralization reaction)

- Gas Evolution reaction

• Oxidation-Reduction reaction (Redox)

- Combination reaction

- Decomposition reaction

- Single displacement reaction

- Combustion of substances in oxygen

Ionic Equations

•In total and net ionic equations, only the

following substances (XX XX)

should be written as ions:

- XX XX salt (based on solubility rule)

- XX XX

- XX XX (these metal hydroxides that

dissolve in water)

•The ions that do not appear in net ionic

equations are called XX XX

Ionic Equations

•In total and net ionic equations, only the

following substances (strong electrolytes)

should be written as ions:

- soluble ionic salt (based on solubility rule)

- Strong acids

- strong bases (these metal hydroxides that

dissolve in water)

•The ions that do not appear in net ionic

equations are called spectator ions

Brönsted-Lowry Acids and Bases

Acids: proton donor

Bases: proton acceptor

In an acid-base reaction, the acid donates a proton

(H+) to the base.

Brönsted-Lowry Acids and Bases

Acids: proton donor

Bases: proton acceptor

In an acid-base reaction, the acid donates a proton

(H+) to the base.

acid base neutralization:

In the reaction of an acid with a base, the H+ from the acid

combines with the OH– from the base to make water.

• This is called an acid-base neutralization reaction.

• The cation from the base combines with the anion from

the acid to make the salt.

acid base neutralization:

In the reaction of an acid with a base, the H+ from the acid

combines with the OH– from the base to make water.

• This is called an acid-base neutralization reaction.

• The cation from the base combines with the anion from

the acid to make the salt.

Gas-Forming Reactions

• Some reactions form a gas directly from the ion exchange

K2S(aq) + H2SO4(aq) ® K2SO4(aq) + H2S(g)

• Other reactions form a gas by the decomposition of one of

the ion exchange products into a gas and water

• H₂S → H₂S(g) (stays together as a gas)

• H₂CO₃ → H₂O(l) + CO₂(g)

• H₂SO₃ → H₂O(l) + SO₂(g)

• NH₄OH → H₂O(l) + NH₃(g)

Gas-Forming Reactions

• Some reactions form a gas directly from the ion exchange

K2S(aq) + H2SO4(aq) ® K2SO4(aq) + H2S(g)

• Other reactions form a gas by the decomposition of one of

the ion exchange products into a gas and water

• H₂S → H₂S(g) (stays together as a gas)

• H₂CO₃ → H₂O(l) + CO₂(g)

• H₂SO₃ → H₂O(l) + SO₂(g)

• NH₄OH → H₂O(l) + NH₃(g)

Rules for Assigning Oxidation States

• rules are in order of priority

1. free elements have an oxidation state = X

• Na = 0 and Cl2 = 0 in 2 Na(s) + Cl2(g)

2. monatomic ions have an oxidation state equal to XX

of the XX

• Na = XX and Cl = XX in NaCl

3. (a) the sum of the oxidation states of all the atoms in a

compound is X

• Na = +1 and Cl = -1 in NaCl, (+1) + (-1) = 0

Rules for Assigning Oxidation States

• rules are in order of priority

1. free elements have an oxidation state = 0

• Na = 0 and Cl2 = 0 in 2 Na(s) + Cl2(g)

2. monatomic ions have an oxidation state equal to charge

of the ion

• Na = +1 and Cl = -1 in NaCl

3. (a) the sum of the oxidation states of all the atoms in a

compound is 0

• Na = +1 and Cl = -1 in NaCl, (+1) + (-1) = 0

Rules for Assigning Oxidation States

3. (b) the sum of the oxidation states of all the atoms in a

polyatomic ion equals the XX of the XX XX

• N = +5 and O = -2 in NO3–, (+5) + 3(-2) = -1

4. (a) Group I metals have an oxidation state of X in all

their compounds

• Na = +1 in NaCl

(b) Group II metals have an oxidation state of XX in all

their compounds

• Mg = +2 in MgCl2

Rules for Assigning Oxidation States

3. (b) the sum of the oxidation states of all the atoms in a

polyatomic ion equals the charge of the polyatomic ion

• N = +5 and O = -2 in NO3–, (+5) + 3(-2) = -1

4. (a) Group I metals have an oxidation state of +1 in all

their compounds

• Na = +1 in NaCl

(b) Group II metals have an oxidation state of +2 in all

their compounds

• Mg = +2 in MgCl2

onmetals have specific oxidation states when they are part of compounds.

Nonmetal	Oxidation state	Exceptions
Fluorine (F)	xx	None in compounds
Hydrogen (H)	xx	−1 in metal hydrides
Oxygen (O)	xx	xx in peroxides (H₂O₂); positive with F
Group 7A (Cl, Br, I)	xx	When combined with F or O
Group 6A (S, Se, etc.)	xx	Exceptions apply
Group 5A (N, P, etc.)	xx	Exceptions apply

onmetals have specific oxidation states when they are part of compounds.

Nonmetal	Oxidation state	Exceptions
Fluorine (F)	−1	None in compounds
Hydrogen (H)	+1	−1 in metal hydrides
Oxygen (O)	−2	−1 in peroxides (H₂O₂); positive with F
Group 7A (Cl, Br, I)	−1	When combined with F or O
Group 6A (S, Se, etc.)	−2	Exceptions apply
Group 5A (N, P, etc.)	−3	Exceptions apply