An introduction to the properties of acids, bases, and the pH scale
ACIDS, BASES, AND PH OH MY!!
COMPLETE THE FOLLOWING TABLE
Element
Atomic #
82
Mass #
Protons
209
16
Uranium
Electrons
238
18
92
Neutrons
Ion,
Isotope, or
Neutral?
MONDAY, SEPTEMBER 17TH
Pick
up the two pieces of
paper from the front table.
ACIDS
Taste
sour
Very reactive
Contain H+ (hydrogen ions)
Examples:
Hydrochloric
Acid (HCl)
Sulfuric Acid (H2SO4)
Citric Acid (citrus fruits)
Acetic Acid (vinegar)
BASES
Taste
Bitter
Feel slippery (soap)
Contain OH- (hydroxide ions)
Examples:
 Soap
 Sodium
Hydroxide (NaOH)
 Ammonia
ACIDS VS. BASES
If
the number of H+ ions in a
solution is greater than number
of OH ions, the solution is an
acid
If the OH ions are greater than
+
the H ions, the solution is a
base
pH SCALE
 Indicates
hydrogen ion (H+) concentration
 Ranges from 0-14
 Acids are found in the 0-6 range
 Bases are found in the 8-14 range
 7 is NEUTRAL!!
1 2 3 4 5 6 7 8 9 10 11 12 13 14
strongest acid
neutral
strongest base
MONDAY, SEPTEMBER 17TH
Do
Now: Get out your pH notes
from Friday.
Testing Day
Tomorrow!!!
pH SCALE
H+ concentration increases
OH- concentration increases
pH SCALE
As you move from pH 0 to pH 14, the
concentration of H+ DECREASES (10 times
each number)
As
you move from pH 0 to pH 14, the
concentration of OH- INCREASES (10 times
each number)
PRACTICE
1.
2.
3.
As you move from pH 7 to pH 4 what
happens to H+ concentration?
As you move from pH 2 to pH 8 what
happens to OH- concentration?
How much more acidic is a solution with
a pH 1 vs. pH 5?
TESTING pH

pH paper OR litmus paper
BUFFERS
Neutralize acids and bases
 Keep the pH from undergoing large changes

PRACTICE AND LAB
Practice: Read the entire article. Write the main
point for each paragraph under the paragraph.
 Lab:

 Make
a prediction for each substance.
 Move around to each station and dip the pH paper
into the solution.
 Use the scale to determine the pH of each
substance.
LAB
Liquid
 1. White milk
 2. V-8 Juice
 3. Comet cleaner
 4. Vinegar
 5. Baking Soda
 6. Water
 7. Egg
 8. Lime Juice

Prediction
________
________
________
________
________
________
________
________
Actual pH
________
________
________
________
________
________
________
________
POST LAB QUESTIONS
1.
2.
3.
4.
Which solution was the strongest acid? The
strongest base?
Which solution was the weakest acid? The
weakest base?
Did you predict that any solution would be
neutral? Was your prediction correct?
Explain.
How many of your predictions were
confirmed during the lab? Explain.