Characteristics of Acids: Table K Electrolytes pH scale: less than 7 Litmus: RED Phenolphthelein: colorless Contains a high concentration of Hydrogen

ions (H+) or Hydronium Ion (H3O+)

H2O + H+ = H3O+

React with certain metals to produce hydrogen gas (H2) – TABLE J

Metal must be higher than H2 to react

Characteristics of Bases: Table L

Electrolytes pH scale: greater than 7 Litmus: BLUE Phenolphthelein: pink Contains a high concentration of

Hydroxide ions (OH-) Tastes bitter; feels slippery/soapy

Characteristics of Salts An ionic compound that has positive ions

other than hydrogen (H+) and negative ions other than hydroxide (OH-).

Example: NaCl (Na+ and Cl-).

Salts conduct electricity (salts are electrolytes).

ACIDS, BASES & SALTS ARE ELECTROLYTES

Beware of Tricks . . . Organic Acids have a functional group –

COOH, so when you see a compound with carbon and this functional group it is an acid!!

Ex: CH3COOH

Alcohols have a functional group –OH (hyroxyl), not OH- (hydroxide); alcohols are not bases!!

Ex: CH3OH

Table K Table L

Strong Acids & Bases HCl HBr HI HNO3 H2SO4

HClO3

HClO4

NaOH KOH Ca(OH)2

LiOH RbOH CsOH Ba(OH)2

NH3 is a weak base!!

ARRHENIUS THEORY OF ACIDS & BASES

An Arrhenius Acid has H and releases Hhas H and releases H++ in in

an aqueous solution.an aqueous solution. The HThe H++ ion is the only positive ion in these ion is the only positive ion in these

solutions. The Hsolutions. The H++ ions are always attached ions are always attached to Hto H22O forming HO forming H33OO++ (hydronium ions). (hydronium ions).

An Arrhenius base has OH (hydroxide) and has OH (hydroxide) and releases OHreleases OH- - (hydroxide ion) in an aqueous (hydroxide ion) in an aqueous solution.solution.

The OHThe OH-- ion is the only negative ion in these ion is the only negative ion in these solutions.solutions.

Bronsted-Lowry Theory Bronsted-Lowry Theory (Alternate Acid-Base (Alternate Acid-Base

Theory)Theory)

BBasesases

AAcceptccept

AAcidscids

DDonateonate

Bases:Bases: H H++ acceptor acceptor (proton acceptor) (proton acceptor)

Acids:Acids: H H++ donor (proton donor (proton donor)donor)

Conjugate Acid Base Pairs

1. NH4+ + OH- → NH3 + H2O

2. H3PO4 + NO2- → HNO2 + H2PO4

-

3. HI (aq) + H2O (l) → H3O+ (aq) + I- (aq)

Some substances can sometimes act like an acid and sometimes act like a base. Examples are H2O & HSO4

-

Neutralization Reactions ACID + BASE = WATER + SALT (IONIC

SOLID)

Titration Titration is a lab process

in which a volume of a solution of known concentration is used to determine the concentration of another solution.

MMAAVVAA =M =MBBVVBB

Example 1:Example 1: What is the molarity of HCl (aq) if 10. milliliters of

4.0 M NaOH (aq) neutralizes exactly 20. milliliters of HCl (aq)?

Example 2:Example 2: What is the molarity of NaOH (aq) if 10. milliliters

of 2 M HBr (aq) neutralizes exactly 5. milliliters of NaOH (aq)?

pH Scale Movement from one whole number to

the next represents a change by a power of 10.

Acids: 1-7, [H3O+] > [OH-] Neutral: 7, [H3O+] = [OH-] Bases: 7-14, [H3O+] < [OH-]

Meaning of pH & pOH

pH = -log[H+]

pH = -log[1.0X10-5] = -(-5) = 5 The solution is acidic.

pOH = -log[OH-] pOH is the concentration of OH- instead of

the concentration of H+

pH + pOH = 14