1. Acids and Bases

2. Properties of Acids
In aqueous solutions, they conduct electricity They are ______________
Metals above H2 on Table J will react with acids to produce hydrogen gas and a salt
Will Mg react with HCl? _________
Will Cu react with HCl? _________
Acids cause color changes in acid-base indicators
Acids react with bases to form a salt + H2O _________
sour taste
pH levels __________
Common examples:___________________________
Table K

3. Properties of Bases
In aqueous solutions, bases conduct electricity  They are also ______________
Bases cause color changes in acid-base indicators.
Bases react with acids to form a salt + H2O!! ____________________________
bitter taste
pH levels ___________
Common examples: ____________________
Table L

4. Properties of Salts
Like acids and bases, salts are also _________________
Salts are formed as a product of neutralization reactions
Neutral  most have a pH of _______
Salts are ionic compounds
( _______+ _______)
Examples:

5. The Arrhenius Theory Svante Arrhenius
Based his ideas on the fact that aqueous solutions of acids and bases are electrolytes
said that the properties of acids and bases are because of their H+ and OH- ions

6. Arrhenius Acids
An acid is a substance that has H and releases (yields) H+ ions as the only positive ions in solution
Adding an acid to an aqueous solution ___________ the concentration of H+ ions in the solution
The H+ ions attach to H2O, forming hydronium ions _________
Examples: ___________________
Can be monoprotic or diprotic________

7. Arrhenius Bases
A base is a substance that has OH and releases (yields) OH- ions as the only negative ions in an aqueous solution
Adding a base to an aqueous solution __________ the concentration of OH- ions in the solution
Examples: __________________

8. The Bronsted-Lowry Theory
Arrhenius’ theory had some limitations, so they expanded the definitions of acids and bases
An acid is an H+ donor
A base is an H+ acceptor
H+ is simply a proton which interacts strongly with nonbonding e- on the oxygen of a water molecule
Interaction results in a hydronium ion H3O+

9. Bronsted-Lowry
Acids and bases can be defined in terms of ability to donate protons
Acid: proton donor
Base: proton acceptor

10. Bronsted- Lowry HCl(g) + H2O(l)  H3O+(aq) + Cl- (aq) EXAMPLE
HCl: _______ H2O: _______

11. Comparing the two theories
NH3(aq) + H2O(l)  NH4+(aq) + OH- (aq)
According to Arrhenius, NH3 is a base because adding it to water increases the hydroxide ion concentration
Bronsted-Lowry classifies it as a base because it accepts a proton from H2O, and the water acts as an acid because it donates a proton

12. Amphoteric Substances
Substances that can act as an acid or base
Ex: H2O
With ammonia it’s an acid
With HCl it’s a base

13. The Meaning of pH
pH measures the H+ ion concentration in a solution. If…..
[H+] = [OH-] ______________________
[H+] > [OH-] ______________________
[H+] < [OH-] ______________________
An increasing pH means the H+ ion concentration is _________
A decreasing pH means the H+ ion concentration is _________
The pH scale is logarithmic
Each change of a single pH unit signifies a TENFOLD change in the concentration of H+ ions
A solution with a pH of 4 is 10x more acidic than a pH of ___
A solution with a pH of 7 is 100x more acidic than a pH of __

14. Calculations with pH
Examples: Determine the pH given the [H+] concentration
1. If [H+] = 1 x pH = ___________
2. If [H+] = 1 x pH = ___________
3. If [H+] = 1 x pH = ___________
4. What is the pH of a M HCl solution? _________
5. What is the pH of a M solution? _________
6. What is the pH of a M solution? _________

15. Neutralization Reactions
When an acid reacts with a base to produce salt and water
It occurs when there are the same amount of H+ ions as OH- ions
General formula: acid + base  water + salt

16. Writing Neutralization Reactions
Take the H+ from the acid and the OH- from the base and combine them to form H2O
Then combine the other ions to form the salt
Remember to look at oxidation numbers!!!!
Make sure the equation is balanced
When a solution is neutral, the moles of H+ = moles OH-
Ex: HCl + KOH  ___________________
Ex: H2SO4 + NaOH  ___________________

17. Acid-Base Titration
A laboratory technique used to achieve neutralization between an acid and a base
It is used to find the unknown molarity of an acid or a base by slowly adding measured volumes of an acid or base of known molarity until neutralization occurs
End point: The point when the indicator changes color
nHMAVA = nOHMBVB

18. Examples
How many milliliters of 4.00M NaOH are required to exactly neutralize 50.0mL of a 2.00M solution of HNO3?
If it takes 55mL of 0.1M NaOH solution to neutralize 450mL of an H2SO4 solution of unknown concentration, what’s the molarity of the acid?

19. Table M Examples You put bromcresol green
in a solution  it turns blue
Then you put bromthymol
blue in the same solution 
it turns yellow
What is the pH of the solution? _____________
Is the solution acidic or basic? _____________
A solution turns yellow with thymol blue and blue with bromthymol blue.
What is the pH of th\e solution? ____________
Is the solution acidic or basic? ____________