1. Acids & Bases
Hammer & Rundell

2. Review: How Do We Set Up an Experiment?
Constants (things that remain the same for all test groups)
Independent Variable
(manipulated or controlled by the experimenter – cause)
Dependent Variable
(depends on the independent variable – effect)
(used as a standard of comparison) Control

3. Graphing the Results
Dependent (y) – Each finger in the group depends on the others.
Independent (x) – Thumb stands
alone relying on no one but himself.

4. Acids and Bases are common
Citrus fruits
Vitamin c
Vinegar
Household cleaners
Stomach acid
Soft Drinks
Bases
Antacids
Household cleaners
Soap

5. Acids and Bases Classifying based on properties
Sour
Corrosive
Bases
Bitter
Slippery

6. Another way to look at acids
Acids donate hydrogen ions when dissolved in water
Bases donate hydroxide ions when dissolved in water.
HCl  H+ + Cl- (acid)
NaOH  Na+ + OH- (base)

7. Practice Identify as acid or base based on their ionization
Ca(OH)2  Ca OH-
HBr  H Br-

8. Acids Ionize in Water: HBr  H+ + Br-
The hydrogen will bond with a water molecule to produce hydronium.
H30+

9. Strength of Acids & Bases
The strength of acids & bases is determined by how many hydrogen or hydroxide ions have been produced.
Lots of hydrogen ions = strong acid
Lots of hydroxide ions = strong base

10. Measuring Strength of Acids & Bases
We measure the strength of acids and bases using the pH scale.
Acids range from 0 to 7
Bases range from 7 to 14
7 is Neutral

11. pH and Indicators
Indictors are chemicals used to determine the pH of a substance.

12. Acids and Bases neutralize each other
HCl + NaOH  H2O + NaCl
Acid base neutral 
Acids and bases combine to form water and a salt.

13. Our Environment
We have all heard of acid rain. It forms when pollutants such as sulfur oxides combine with water to form sulfuric acid.
Sulfur oxides + water  acid rain

14. Question 1
Where on the pH scale are the acids?
pH Scale

15. Question 2
The directions on a can of oven cleaner say that you must use gloves. The cleaner is slippery and turns litmus paper blue. It is probably a _____.
A. Acid
B. Base
C. Salt
D. isotope

16. Question 3
A beaker contains 100 mL of a solution with a pH = 3. One hundred mL of a second unknown solution is added to the first solution and stirred. The pH of the mixture is now The second solution
A. has a high concentration of hydroxide ions
B. is neutral
C. is a strong acid
D. is a salt

17. Question 4 Which of the following is a base?
A. a substance with a pH = 6
B. A solution with more hydrogen ions than hydroxide ions
C. Ba(OH)2
D. NaBr

18. Question 5
Acid rain is the result of water combining in the atmosphere with sulfur oxides to form sulfuric acid. Which of the following might occur in a region that has acid rain?
A. Lakes have a lower pH than normal
B. Plants die
C. Rocks weather
D. All of the above