1. Acids
Lesson 4
Acid and Base
Definitions

2. Acid and Base Definitions Bronsted Arrhenius Acid Base Acid Base
proton donor proton acceptor ionizes to H+ ionizes to OH-
Strong means completely.
Weak means partially.

3. Definitions
1. Strong Arrhenius Acid-   
completely ionizes in water to H+
HCl 
H+ + Cl-
2. Strong Bronsted Acid-
completely donates a proton to a base
HCl
+ H2O 
H3O+ + Cl-

4. 3. Strong Arrhenius Base-  
completely ionizes in water to OH-
KOH 
K+ + OH-
4. Strong Bronsted Base-
completely accepts a proton from an acid
NH2-
+ H2O 
NH3 + OH-

5. 5. Weak Arrhenius Acid-   
partially ionizes in water to H+ HF
⇄ H+ + F-
6. Weak Bronsted Acid-
partially donates a proton to a base HF
+ H2O ⇄
H3O+ + F-

6. 7. Weak Arrhenius Base-   
partially ionizes in water to OH-
Zn(OH)2
⇄ Zn2+ + 2OH-
8. Weak Bronsted Base-
partially accepts a proton from an acid
NH3
+ H2O ⇄
NH4+ + OH-

7. Acids
Bases
Is NH3 an acid or a base in water?
Base- it is closer to the strong
bases than strong acids

8. Memorize the following
NH3 is a weak base when in water
NH4+ is a weak acid
H2O is an acid when with a base and a base when with an acid and is amphiprotic
H2O is always neutral when pure
Write a reaction showing water acting as an base
H2O + HIO3
⇄ NH4+ + OH-
Write a reaction showing water acting as a acid
H2O + NH3
⇄ H3O+ + IO3-

9. Acid Anhydride
Means an Acid without water
Add water and you get an acid
They are nonmetal oxides
Add water Add the H's and O's Make an acid Simplify
SO2
+ H2O
 H2SO3
CO2
+ H2O
 H2CO3
N2O5
+ H2O 
H2N2O6
 2HNO3

10.   
Cl2O7 + H2O
 H2Cl2O8  2HClO4
C2O3 + H2O
 H2C2O4
 H2I2O6  2HIO3
I2O5 + H2O

11. Basic anhydride
Means a base without water
Add water and you get a base- OH style
They are metal oxides
Add water Add the H's and O's Make a base- start with a metal
K2O + H2O
 2KOH
CaO + H2O
 Ca(OH)2
Na2O + H2O
 2NaOH
BaO + H2O
 Ba(OH)2

12. Classify each formula and write an equation.
strong acid weak acid strong base
weak base acid anhydride basic anhydride.
HNO3
CO2
Mg(OH)2
H2C2O4
Strong acid
HNO3  H NO3-
Acid Anhydride
CO2 + H2O  H2CO3
H2CO ⇄ H+ + HCO3-
Strong Base
Mg(OH)2  Mg OH-
H2C2O ⇄ H+ + HC2O4-
Weak Acid

13. Classify each formula and write an equation.
strong acid weak acid strong base
weak base acid anhydride basic anhydride.
Rb2O
Basic Anhydride
Rb2O + H2O  2RbOH
RbOH  Rb OH-
NH2-
Strong base
NH H2O  NH OH-
CN-
Weak base
CN H2O ⇄ HCN + OH-
NaOH  Na OH-
NaOH
Strong base