Authentic Web-Based Lesson & Project Based Learning Approach

1. A N A U T H E N T I C I N T E R N E T - B A S E D L E S S O N
A N D P R O J E C T B A S E D L E A R N I N G A P P R O A C H
Acids, Bases, & Salts

2. Learning Objectives
Students will be able to:
 Generate or interpret molecular representations (words
and/or pictures) for acid or base solutions
 Provide or use representations of the relative amounts of
particles in acid or base solutions to estimate strength
and/or concentration
 Use common tools (pH meter, conductivity, pH paper) of
acid or base solutions to estimate strength and/or
concentration

3. Specifically,
• Compare/contrast acids and bases of varying strength. (Given acids or bases
at the same concentration)
• Compare/contrast acids and bases of varying solution concentration. (Given
acids or bases of the same strength)
• Compare/contrast acids and bases of varying strength and concentration
combinations. (Given examples like: Concentrated solution of a weak acid or
base; Concentrated solution of a strong acid or base; Dilute solution of a weak
acid or base; Dilute solution of a strong acid or base
• Give examples of different combinations of strength/concentrations that result
in same pH or conductivity values.

4. Background
 This lesson is part of an ongoing investigation of acids, bases, and salts.
 Students will further investigate the properties of acids and bases.
 Students will have already tested household products they brought in from home, and
used pH paper/Universal Indicator to determine the pH of those substances.
 Students learned about acids, bases and the pH scale by using indicators to test different
beauty products that are sometimes advertised as “pH-balanced” (e.g. shampoos,
deodorants, etc.).
 Students were able to discover that the phrase “pH-balanced” has no meaning.
 Students created individual spreadsheets that we compiled into a large data table. Taken
collectively, students were able to see that some beauty products are weakly acidic, some
are weakly basic, and some are neutral.
 Students should be able to correlate acidity with lower pH’s and alkalinity with higher
pH’s.

5. Engaging
Students with a
demonstration.
This demonstration
will show students
that NYC tap water
really is as good as it
gets. Students are very
familiar with both
bottled and tap water.
This is a great
demonstration that I
developed accidently
while running through
an experiment at
home. It is a
discrepant event that
students will really be
surprised from.
NYC tap water vs. Bottled water

6. phET Acid-Base Solutions Activity
 Students are referred to the worksheet
handout.
 Students work in pairs to answer the
worksheet using the phET simulation.
 Students are encouraged to discuss their
observations with their partners.
 At the end of the activity, students are
presented with clicker questions on a
series of powerpoint slides
Student directions Acid Base Solutions: Concentration and Strength
http://phet.colorado.edu
4/17/2016 Loeblein Some materials adapted from an activity by Lancaster /Langdon
Learning goals: Students will be able to
a) Generate or interpret molecular representations (words and/or pictures) for acid or base solutions
b) Provide or use representations of the relative amounts of particles in acid or base solutions to
estimate strength and/or concentration
c) Use common tools (pH meter, conductivity, pH paper) of acid or base solutions to estimate
strength and/or concentration
Prelab:
1. Water molecules are not shown. Each beaker contains the same volume of solution;
Key: = HA (unreacted acid) = A-
= H+
(or H3O+
)
1a.Which might be the label on Beaker C?
A. 0.01 M HC2H3O2 B. 0.1 M HC2H3O2 C. 0.3 M HC2H3O2 D. 0.01 M HCl E. 0.3 M HCl
1b. Which beaker would have the lowest pH? A B C D
1c. Explain your reasoning: for both questions
2. You have two beakers. One beaker contains 100 mL of NaOH (a strong base);
the other contains 100 mL of aqueous Na3PO4 (a weak base). You test the pH of
each solution. Which of the following statements is true?
a. The Na3PO4 has a higher pH because it has more sodium ions than NaOH.
b. It is possible for the solutions in each beaker to have the same pH.
c. If the pH of the NaOH solution is 12.00, the pH of the Na3PO4 solution has
to be greater than 12.00.
d. If the pH of the NaOH solution is 12.00, the pH of the Na3PO4 solution has to be less than 12.00.
Explain your reasoning.
Lab: Visualizing acid strength, concentration, and pH
A. Explore the simulation with your group and discuss these questions. Use the molecular view, pH,
conductivity, and bar graphs.
1. For an acid, what happens to the molecule when it is in a water solution?
2. What is different about what happens to a weak acid molecule and what happens to a strong acid
molecule?
3. How do the representations of a weak acid reaction differ from a strong one?
4. If you increase the concentration of an acid, what changes in both types of acids?
Beaker A
0.1 M HCl
Beaker B Beaker C Beaker D
100 mL 100 mL
NaOH(aq) Na3PO4(aq)

8. Project Discussion
 Students will use their acquired knowledge of acids and bases
to create two videos about a household item.
 Students will work in groups of 4 and select a household item
from a list, gather information, and create two videos about
their item, geared towards specific audiences.
 In groups, students will decide which of their previous middle
school teachers they would like to show their video to for
evaluation.
 Together they will compose an email to send this teacher
requesting participation.

9. Household Item Choices
(May select another, but it must be colorless in aqueous solution and
approved by me first)
Sprite Soda Ammonia White Vinegar Aspirin
Seltzer Windex Washing Soda Tums

10. Topics to include in filming, but not limited to:
 Middle School Video
 General properties of acids and bases; conductivity
 Arrhenius definition of Acids and Bases; dissociation equations
 Classify household item as an Arrhenius acid or base; or if it doesn’t fit
the definition, explain why
 Describe the pH scale and what it tells us; test results of acids, bases,
and household item with litmus paper, universal indicator
 High School Video
 pH and pOH calculation (how to do the calculation; then do this for the
household item)
 Bronsted-Lowry definition of acids and bases; balanced hydrolysis
equation
 Degree of dissociation (strong or weak); degree of conductivity
 Neutralization reaction (write balanced neutralization equation with
states)
 Results from titration lab with household item

11. 4-5 points 3 points 2 points 1 points # points
earned
Creativity and Use of
Media (music, art,
acting, computer
graphics, etc)
-very creative
-very original
-visible effort put in
to make it
interesting
-strong use of media
to enhance interest
-somewhat original /
creative
-visible effort put in
to make it
interesting
- good use of media
to enhance interest
-somewhat creative
-some originality
- some effort put in
to be creative, could
be better
-little to no use of
media
-little to no creativity
or originality
- little to no effort
put in to make video
interesting
-little to no use of
media
Oral Presentation -very well practiced
and planned
-fluid pace
-not awkward
-little to no “dead
time”
- well practiced and
planned
- not awkward
- little to no “dead
time”
- practiced, but could
be better
- some awkwardness
- some dead time
-not practiced
-could be better
prepared
-awkward
-a lot of dead time
Middle School (MS)
Level
- MS students
understand the main
points very well,
including most or all
specific facts in the
video
- MS students
understand the main
points, but may be
unclear on a few
specific facts in the
video
- MS students
understand some
main points, but are
unclear on many
specific facts in the
video
-MS students do not
understand the
majority of the video.
The main points of
video are unclear
Rubric for Middle School Video

12. Name AND formula
of chemical given (2
pts)
-Name of chemical
given
-Correct formula of
chemical given
# Points Earned=
Properties of chemical
given (10 pts)
-Acid or base?
-Strong or weak?
-Results of test with light bulb
tester?
-Explain how you know that it’s
strong or weak?
-Degree of dissociation (high or
low) and relation to strength?
- Results of test with pH paper?
- What pH was it?
- [H+] concentration?
- [OH-] concentration?
- Results of tests with red and blue
litmus paper
Arrhenius Theory
(3 pts)
- Identify as Arrhenius acid or
Arrhenius base, or neither
- Explain your identification (2 pts)
Bronsted Theory
(3 pts)
- Identify as Bronsted acid or
Bronsted base
- Explain your identification (2 pts)
Rubric for Chemistry Class Video