1. Acids Give foods a sour or tart taste
Vinegar (acetic acid)
Lemons (citric acid)
Aqueous solutions of acids are electrolytes
Conduct electricity
Causes indicators to change color
Metals react with acids to produce hydrogen gas

2. Bases Have a bitter taste Feel slippery
Soap
Feel slippery
Aqueous solutions of bases are electrolytes
Cause indicators to change color
Neutralize an acid

3. Arrhenius Acids
Hydrogen containing compounds that ionize to yield hydrogen ions (H+) in aqueous solutions
Only hydrogens in very polar bonds are ionizable
When hydrogen is joined to a very electronegaive element
Acids that produce one ionizable hydrogen are known as monoprotic acids (ex: HNO3)
Acids that produce 2 ionizable hydrogens are known as diprotic acids (ex: H2SO4)
Acids that produce 3 ionizable hydrogens are known as triprotic acids (ex: H3PO4)

4. Arrhenius Bases
Compounds that ionize to yield hydroxide ions (OH-) in aqueous solutions
Alkali metals react with water to produce solutions that are basic
Na + H2O  NaOH + H2

5. Hydrogen Ions from Water
Reactions in which water molecules produce ions is called the self-ionization of water
H2O  H+ + OH-
Hydrogen ions will join with water molecules to form hydronium ions (H3O+)
In pure water, the equilibrium concentrations of H+ and OH- are each only 1.0×10-7 M
This is considered to be a neutral solution

6. Ion Product Constant for Water
When [H+] increases, [OH-] decreases and vice versa
For aqueous solutions, the product of [H+] and [OH-] equals 1.0×10-14 M
This is called the ion product constant of water (Kw)
Kw = [H+] × [OH-] = 1.0×10-14 M
When [H+] is greater than [OH-] --- acidic solution
[H+] is greater than 1.0 ×10-7 M
When [OH-] is greater than [H+] --- basic solution
[H+] is less than 1.0 ×10-7 M

7. Problems
The concentration of hydroxide ion is found to be 1.0×10-11 M. Find the concentration of hydrogen ion and determine if the solution is acidic, basic, or neutral.

8. Problems
Calculate the concentration of the other ion and classify the solution as acidic, basic, or neutral.
a. [OH-] = 1.0×10-6
b. [H+] = 1.0×10-7
c. [H+] = 8.1×10-3

9. The pH concept Ranges from 0 to 14 Neutral solutions have pH = 7
pH = 0, strongly acidic
pH = 14, strongly basic
ACID
BASE

10. Calculating pH
pH of a solution is the negative logarithm of the hydrogen ion concentration
pH = -log [H+]
[H+] = 1.0 ×10-7  pH = 7
pH > 7, basic
pH < 7, acidic
If [H+] is written in scientific notation and has a coefficient of 1, then the pH of the solution equals the exponent
[H+] = 1.0 ×10-2  pH = 2 (acid)
If pH is an integer number, you can directly write the [H+]
pH = 9  [H+] = 1.0 ×10-9

11. Calculating pOH
pOH of a solution is the negative logarithm of the hydroxide ion concentration
pOH = -log [OH-]
pOH = 7, neutral
pOH < 7, basic
pOH > 7, acidic
pH + pOH = 14

12. Problems
A carbonated soft drink is found to have a hydrogen ion concentration of 7.3 ×10-7 M, what is the pH and pOH of the drink?

13. Problems
Calculate the pH and pOH of the solutions below and classify as acid, base, or neutral.
[H+] = 1.0 ×10-2
[OH-] = 5.6 ×10-8
[H+] = 2.7 ×10-3
[OH-] = 0.61 M

14. Neutralization Reactions
Reactions in which an acid and a base react in aqueous solution to produce a salt and water
Salts are compounds that consist of an anion from an acid and a cation from a base

15. Titration
Process of adding a known amount of solution with a known concentration to determine the concentration of another solution
Solution of known concentration is the standard solution
Point at which the indicator changes color is the end point
Only have water and salt remaining, plus a trace of indicator
pH = 7
When moles of hydrogen ions = moles of hydroxide ions you have reached the equivalence point

16. Problems
In a titration, 53.7 mL of a M HCl solution is needed to neutralize 80 mL of KOH solution. What is the molarity of the KOH solution?

17. A 45 mL sample of nitric acid solution is neutralized by mL of M NaOH solution. What is the molarity of the nitric acid solution?
A 70 mL sample of sulfuric acid solution is neutralized by mL of M NaOH solution. What is the molarity of the sulfuric acid solution?