Transcript Cultivating Conceptual Chemical Thinking: Can You Visualize It?

Cultivating Conceptual Chemical
Thinking: Can You Visualize It?
Scott A. Sinex & Barbara A. Gage
Department of Physical Sciences
Prince George’s Community College
Presented at the Middle Atlantic Regional Meeting of the American Chemical
Society held at George Mason University in Fairfax, VA on 28-30 May 2002.
Building A Conceptual Understanding
Microscopic –
the particulate
nature of matter
The atomic level
(abstract)
Symbolic –
mathematical
equation or
chemical equation
Macroscopic observations or
results of an
experiment
How we represent it
The visible world or
How we SEE it
What we want students to do
Model data with algebra
Use graphical approach with simulations
Use science process
Understand concepts
Visualize at an atomic/molecular level
Think critically!!
Integrating Technology as a
Learning Enhancement Tool
TEACHING
Bloom’s Taxonomy
Evaluation
Synthesis
Analysis
Application
Comprehension
Knowledge
LEARNING
TECHNOLOGY
Instructional Uses
Modeling & Simulations
Animations
Data Collection and Graphing
Web Searches
Drill & Practice
Or
“Drill and Kill”
Integration
Enrichment
Automation
Modified from Barry Adams, Apple Computer
The following is a text of
the emergency chemistry
instruction system.
This is only a test!
Can you hit the bull's-eye?
Three shooters
with three
arrows each to
shoot.
How do they
compare?
Both
accurate
and precise
Precise
but not
accurate
Neither
accurate nor
precise
Can you define accuracy and precision
based on the graphics above?
How does the mass influence the vibration?
H2
MM = 2 g/mole
4111 cm-1
I2
MM = 254 g/mole
365 cm-1
The greater the mass - the lower the wavenumber
Estimate the wavenumber for the HI stretch.
2919 cm-1
Have you ever tried explaining the derivative to students?
HCl + NaOH  NaCl + H2O
The slope between each pair of data points.
pH
inflection point - changed
from increasing to decreasing
decreasing slope
7
increasing slope
How is the slope changing?
Volume of titrant (mL NaOH)
How about intramolecular interactions?
(Click on image to load movie- slow, big file)
di-t-butyl peroxide
Movie produced
in Spartan ‘02
Discovering Intramolecular
Interactions – html activity
Can vibrations change the dipole of a molecule?
(Click on image to load movie- slow, big file)
Dipole moment
CH2Cl2
Cl-C-Cl bond angle
Movie produced
in Spartan ‘02
Studying Vibrations in
Molecules – html activity
The tools of conceptual
visualization
• Animation in PowerPoint XP
• Spartan ’02 computational chemistry
software
• Stella modeling and simulation software
• Interactive Excel spreadsheets
• Chime molecular rendering freeware
• Netlogo simulation freeware
• Flash animation software (future effort)
Click on links above for information/download of software.
Netlogo gas
particle motion
Interactive Excel:
Weak Acid Behavior
Beers Law Simulator
(pdf activity using
simulator)
Structure and Bonding –
a series of Chime activities
Stella model for
crystal violet kinetics
What are our outcomes?
Web-based interactive assignments –
both in and out of class
More student involvement in class and lab –
they are engaged!
More integration of mathematics
Can ask higher-order questions
Let’s look at an example
A higher-order thinking example:
For the calibration of pH electrode:
E = E’ – 0.0591 pH
How does the measured voltage, E, vary with pH?
How does the graph change if the glass membrane
ages with time?
What is influenced by a
E’
change in temperature?
new E ’
E
Slope = -0.0591
new slope
pH
E ’ is function of
temperature too!
Department of Physical Sciences – downloadable
resources at http://academic.pg.cc.md.us/psc
Scott Sinex ([email protected])
http://academic.pg.cc.md.us/~ssinex
see teaching and publications list
Barb Gage ([email protected])
http://academic.pg.cc.md.us/~bgage
see courses taught