1. And the Indicators that tell the story….
Acids & Bases
And the Indicators that tell the story….

2. Acids & Bases are Based on WATER!
Depending on the amount of H+ or OH- ions, the “water” becomes either acidic or basic (aka alkaline)
The pH scale determines the strength of the acid/base
The pH scale runs from 0 -14
Low numbers are acidic
High numbers are alkaline
“7” is neutral  Water

3. Acids
Acids are a chemical substance which contains more H+ ions than OH- ions.
An acid is able to donate electrons
H+ is called Hydronium
The more H+ ions in solution, the stronger the acid.

4. Bases (Alkali)
Bases are a chemical substance which contains more OH- ions than H+ ions.
A base is able to accept electrons
OH- is called hydroxide
The more OH- ions in solution, the stronger the base.

5. The pH Scale

6. Characteristics of Acids
Taste Sour
Conduct Electricity
Corrosive, which means they break down certain substances. Many acids can corrode fabric, skin and wood
Some acids react strongly with metals
Turns blue litmus paper red
Turn pH Paper Yellow  Red
Depending on strength of acid

7. Acids
Remember… Acids are solutions with a higher amount of Hydrogen ions (H+)
99% of the time, their formula begins with “H” (which stands for the Hydrogen ion)
HCl = Hydrochloric Acid
HNO3 = Nitric Acid
H2SO4 = Sulfuric Acid

8. Characteristics of Bases aka - Alkalis
Feel Slippery (Think SOAP!)
Taste Bitter
Corrosive (Just as corrosive as Acids!)
Can conduct electricity. (Think alkaline batteries.)
Do not react with metals
Turns red litmus paper blue
Turn pH paper Green  Blue
Turn Phenolphthalein  Pink/Magenta

9. Bases
Remember… Basic (Alkali) solutions have a higher amount of Hydroxide ions (OH-)
99% of the time, their formula ends with “OH” (which stands for the Hydroxide ion)
NaOH = Sodium Hydroxide
KOH = Potassium Hydroxide
Ba(OH)2 = Barium Hydroxide

10. To Neutralize…
Neutralization is a chemical reaction in which an acid and a base react with each other
In a neutralization reaction, the point is to bring the solution back to equilibrium
No excess of hydrogen or hydroxide ions present in solution
One “H+” for each “OH-”…
H+ OH = Water! (Which is neutral)

11. Neutralization To neutralize (counter-act) an acid, you add a base
To neutralize (counter-act) a base, you add an acid
A Neutralization Reaction always produces a salt and water!
Acid + Base = Salt + Water
Neutralization is a type of Hydrolysis (breaking something apart and producing water (hydro) as one of the products)

12. Salts A salt is formed between the reaction of an acid and a base
Usually, a neutral salt is formed when a strong acid and a strong base are neutralized in the reaction
The H+ is removed from the acid and the  OH- is removed from the base
H + OH = H2O
The other elements combine to form a salt
A salt is an ionic compound which is made up of two groups of oppositely charged ions
A Metal + A Non-metal 

13. Salts CAN BE acidic or basic (or neutral)!
Adding a strong acid to a strong base should bring the pH of the solution back to neutral
A salt formed between a strong acid and a weak base is an acid salt
A salt formed between a strong base and a weak acid is a basic salt

14. What happens when…
What happens when a solid salt solution is dissolved in water?
It is hydrolyzed (broken down) into an acid and a base
Example: NaCl (Sodium Chloride) – Table Salt
In water, it is broken into Na+ and Cl- ions
The Sodium (Na) metal and a Hydroxide ion (OH) combine to form a base (NaOH)
The Chlorine (Cl) non-metal and a Hydrogen ion (H) combine to form an acid (HCl)

15. Litmus Paper (Red & Blue)
Indicators
Acid - base indicators (aka pH indicators) are substances which change color in different pH levels
There are many different types of indicators:
Litmus Paper (Red & Blue)
pH Paper
Universal
Bromothymol Blue
Thymol Blue
Methyl Orange
Phenolyphthalein
Bromocresol Green

16. Indicator Acid Neutral Base
Red Litmus
Blue
Red
Blue Litmus
Universal Indicator
Red/Brownish
Green
Blue/Violet
Bromothymol Blue
Yellow
Methyl Orange
Orange
Phenolphthalein
Clear/Colorless
Pink/Magenta
Thymol Blue
pH Paper
Reddish/Brown
Navy