1. Acids, Bases, Salts
An introduction

2. Properties
Acids: sour taste, react with some metals to produce hydrogen gas; aqueous solutions of acids are electrolytes
Bases: bitter taste, slippery feel; aqueous solutions of bases are electrolytes

3. Arrhenius acids and bases
Acids ionize to yield H+ ions (aq)
Bases ionize to yield OH- ions (aq)
This is a narrow definition!

4. Arrhenius acids Acid types: Monoprotic: one ionizable hydrogen
Diprotic: two ionizable hydrogens
Triprotic: three ionizable hydrogens

5. Arrhenius bases Most are hydroxides of metals IA salts dissociate well
IIA salts dissociate poorly

6. Bronsted-Lowry Acids and Bases
Acid: hydrogen ion donor
Base: hydrogen ion acceptor
Realization: Bronsted-Lowry and Arrhenius acids/bases are not necessarily the same!
Example of base: ammonia: NH3 becomes NH4+

7. Conjugate acids and bases
A conjugate acid is the particle formed when a base gains H+.
A conjugate base is the particle that remains when an acid has donated H+.
A conjugate acid/base pair consists of two substances related by the gain/loss of H+.
Remember: water is a H+ acceptor, so it is a B/L base. Forms hydronium ion, H3O+

8. Amphoteric substances
Substances which can be either an acid or a base
Water is amphoteric: can either gain or lose H+

9. Lewis Acids and Bases
Acid: accepts a pair of electrons during a reaction
Base: donates a pair of electrons
When they do this, a covalent bond forms

10. Hydrogen Ions and Acidity
Self-ionization: water breaking down into H+ and OH-
When [H+] = [OH-], pH is neutral.
Ion Product Constant:
H+ (aq) + OH- (aq)  H2O (l)
Kw = [H+][OH-] =1.0x10-14
If an acid, [H+] > 1x10-7
If a base, [H+] < 1x10-7

11. pH and pOH pH = -log [H+] If pH>7, basic/alkaline
If pH<7, acidic
pOH = 14 – pH
For calculations, use scientific notation!

12. Measuring pH
Indicators: substances which can form both acids and bases in solution, depending upon the concentration of H+
Endpoint: pH where an indicator changes its color
pH meters: instruments which measure [H+]

13. Strengths of Acids and Bases
Strong a/b: dissociate completely (form ions totally) in solution
Weak a/b: only dissociate/ionize slightly

14. Strengths of Acids and Bases
Acid Dissociation Constant:
Keq= [H3O+][A-]
[H2O][HA]
These are called Ka values, acid dissociation constants.
The stronger the acid, the larger the Ka value.
Same for bases.
Dissociation constants: substitute into formula to find unknowns

15. Neutralization reactions
Acid/base reactions
Acid + base -> salt + water
Titrations: determine equivalence point, where the moles H+ equal moles OH-.
This equalization point is shown with an indicator, discussed earlier, called an endpoint

16. Salts in Solution Salt Hydrolysis: splitting apart in water
Some solutions of salts are neutral, some acidic, some basic.