1. How can one distinguish between acids, bases, and salts?

2. Electrolytes: Form ions in water
Aqueous solutions can conduct electricity
Salts:
Ionic Compounds
May Include Polyatomic Ions
M+ to NM-
Acids:
Bases:
pH < 7
[H+] > [OH-]
pH > 7
[OH-] > [H+]

3. Look in Reference Table for Common Acids and Bases!
Ask me how to recognize acids / bases / salts

4. Naming Acids: 1) If the acid does not have oxygen: hydro____ic acid.
(includes all binary acids)
Start with the prefix hydro- followed by the root of the anion and the suffix -ic, and add the word acid.
Ex. HCl – hydrochloric acid
HI – hydroiodic acid
H2S – hydrosulfuric acid
hydro____ic acid.
2) If the acid does have oxygen:
(the anion is a polyatomic ion containing the element oxygen)
Start with the root of the central atom in the polyatomic ion (Table E) and add the appropriate suffix followed by the word acid.
Ex. H2SO4 – sulfuric acid
H2SO3 – sulfurous acid
HClO – hypochlorous acid
Suffix: -ate  -ic
-ite  -ous

5. Characteristics of Acids and Bases:
Taste sour (vinegar, lemons)
Electrolytes in solution
React with some metals to produce H2(g)
Mg + HCl  MgCl2 + H2 (SR reaction)
Taste bitter
Feel slippery
Electrolytes in solution

6. Bases Acids Arrhenius Theory Definitions:
A substance that when dissolved in water produces the H+(aq) ion as the only positive ion in solution.
Ex. HCl(aq)
A substance that when dissolved in water produces the OH-(aq) ion as the only negative ion in solution.
Ex. NaOH(aq)

7. Acids Bases Bronsted-Lowry Theory Definitions:
Based on the proton (H+)
Acids
Bases
A proton acceptor.
It must have a lone pair of electrons.
A proton donor.
It must release the H+ ion from its structure.
Ex. HCl + H2O  H3O+ + Cl-
Ex. NH3+H2O  NH4+ + OH-

8. Conjugate Acid / Base Pairs:
Two species are nearly identical, but they differ exactly by ONE H+ ion (proton)
Remember Bronsted-Lowry: Acid is H+ donor, base is H+ acceptor
Ex. If HCl is the acid, what is its conjugate base?
Ex. What is the conjugate acid of HSO4-?
Ex. What is the conjugate acid of SO42-?
Ex. In the forward reaction, what is the acid?
HNO3 + NH3  NO3- + NH4+
What is its conjugate base?

9. Reversible Acid-Base Reactions:
H2SO4(aq) + NH3(aq) HSO4-(aq) + NH4+(aq)
For the forward reaction, what is the Bronsted acid?
(consider which species donates a proton in the forward reaction)
For the reverse reaction, what is the Bronsted acid?
What species from the forward and reverse reactions are the Bronsted bases?
List both conjugate acid-base pairs.

10. Can act either as an acid or a base
Amphoteric Substance:
Can act either as an acid or a base
Water is a common amphoteric substance.
H2O(l) + H2O(l) H3O+(aq) + OH-(aq)
One water molecule acts as an acid while the other acts as a base.
Hydrogen sulfate is another amphoteric substance.
In an acidic environment with excess protons, HSO4- will act as a base and accept a proton.
In a basic environment, HSO4- can act as an acid and donate a proton.

11. Strong Acids: Consider all other acids to be weak! HCl HBr HI HClO4
H2SO4
HNO3
Consider all other acids to be weak!

12. Neutralization: BASE SALT WATER ACID +  + Ex. HCl(aq) + NaOH(aq) 
(for Arrhenius acids and bases)
The reaction between an acid and a base yields a salt and water.
BASE
SALT
WATER
ACID +  +
Ex. HCl(aq) + NaOH(aq) 
NaCl(aq) + H2O(l)
Ex. What are the products of a reaction between sulfuric acid and calcium hydroxide?
Ex. What acid and base were used in a neutralization reaction that produced the salt KNO3?

13. Monoprotic Acids: Polyprotic Acids:
Can only donate ONE proton (H+ ion)
Ex. HCl, HNO3, CH3COOH
Polyprotic Acids:
Can donate more than one proton (H+ ion)
Diprotic acids can donate up to two protons
Ex. H2SO4, H2CO3
Triprotic acids can donate up to three protons
Ex. H3PO4

14. Salts can be neutral, acidic or basic:
Original Acid:
Original Base:
Resulting Salt:
Strong
Neutral
Weak
Acidic
Basic
?? (College)

15. The pH Scale: pH = - log [H+] pH < 7, acidic pH = 7, neutral
Based on the H+ ion concentration in an aqueous solution
If the concentration of H+ ions is 1 x 10-4 M, what is the pH?
pH = - log [H+]
If the concentration of H+ ions is 1 x 10-8 M, what is the pH?
pH < 7, acidic
pH = 7, neutral
pH > 7, basic

16. A decrease of one unit of the pH scale represents a ten-fold increase (x 10) in the H+ ion concentration.
pH = - log [H+]
If the pH of a lake decreased due to acid rain from 6 in 1997 to 4 in 2007, how many times greater is the H+ ion concentration in 2007 compared to the H+ ion concentration in 1997?
100

17. Water molecules ionize to a certain extent: H2O  H+ + OH-
The concentration of the H+ ion is related to the concentration of the OH- ion.
Water molecules ionize to a certain extent:
H2O  H+ + OH-
For pure water, [H+] = [OH-] = 1 x 10-7 M
pH = 7, pOH = 7
pOH = - log [OH-]
Then, [H+] x [OH-] = 1 x = Kw (a constant)
For all aqueous solutions, [H+] x [OH-] = Kw, so [H+] x [OH-] = 1 x 10-14, and pH + pOH = 14.
What is the pH of a solution that has a hydroxide ion concentration of 1 x 10-4 M?

18. “See-Saw Diagram”

19. ia ib In order to be a neutral solution, pH = 7 and pOH =7.
Also, [H+] = [OH-] = 1 x 10-7 M
In other words, a neutral solution has the same number of moles of H+ ions as OH- ions.
Titration equation (when there is a neutralization between an acid and a base): MaVa ia = MbVb ib
(use any unit of volume as long as you’re consistent) ia
represents the number of H+ ions from the acid ib
represents the number of OH- ions from the base

20. Use the titration equation: MaVa ia = MbVb ib
Titrations:
In an acid-base titration experiment, one determines the concentration of an acid or base through neutralization.
Use the titration equation:
MaVa ia = MbVb ib
What is ia if you use 1 M phosphoric acid?
What is ib if you use 1 M calcium hydroxide?

21. How many mL of 0.45 M HCl will neutralize 25.0 mL of 1.00 M KOH?
Practice Titration Problems:
How many mL of 0.45 M HCl will neutralize 25.0 mL of 1.00 M KOH?
What is the molarity of HNO3 if 25.0 mL is completely neutralized by 12.5 mL of standard 0.50 M NaOH?
What is the concentration of H2SO4 if 25 mL of the acid is completely neutralized by 18 mL of standard 1.0 M NaOH?

22. Acid-Base Indicators:
Acid-Base Indicators are used to provide information about the pH of solutions. Also, the indicators can help determine the endpoint (point of neutralization) of an acid-base titration.
Use the pH Range and Color Change Columns together.
Below the range, the color is given on the left, and above the range, the color is given on the right.
What is the color of litmus in a solution that has a pH of 4.0?
pH of 9.0?

23. Methyl Orange –
Bromthymol Blue –
Phenolphthalein –
Litmus -
What is the color of the following indicators in a solution that has a pH of 5.0?
What could be the pH of a solution when methyl orange is yellow, phenolphthalein is colorless, bromcresol green is blue, and thymol blue is yellow?
1, 4, 7, or 11?

24. In the laboratory, phenolphthalein is often used to approximate the endpoint of a titration.
Notice that the color change is from colorless to pink. Thus, it is easy to note when the color change occurs.
Phenolphthalein was added to the acid in the flask, and a standard base drips from the buret. The titration is finished, or the endpoint is reached, when the pink color persists in the mixed solution.