Scaffolding a Conceptual Understanding of the Gas Phase in General Chemistry Enriched

with Technology

Scott A. Sinex and Barbara A. GageDepartment of Physical Sciences and

EngineeringPrince George’s Community College

Presented at the 230th National Meeting of the American Chemical Society in Washington, DC on 28 August - 1 September 2005.

Your objectives in gases…

• Behavior and properties of gases• Introduce the ideal gas law and

combined gas law• Finding molar mass and gas density• Kinetic-molecular theory• Real gas behavior

...but we don’t want to lecture!

Liquids and IMF’s

What & Why?

• Discovery laboratory experience • Build and extend qualitative into

quantitative mathematical relationships• Extend knowledge from ideal gases

into real gases after covering liquids and intermolecular forces

• All steps enriched by using technology• Student- or learner-centered activities

How? or Technology involved...

• Webpage with links and pdf handouts• Multi-layered Interactive Excel• Animations as

– Flash from Odyssey– NetLogo Java applet– Movie from SnagIt (screen-capture

software)

The complete package of materials:http://academic.pgcc.edu/psc/chm101/ideal_gas

• Laboratory activity (<2.5 hours)

• Macroscopic behavior

• Mostly qualitative relationships

• P-V experimental data collected

The Behavior of Gases

P

V PV = k

Our complete General Chemistry I lab manual.

Discovery-based laboratory activity

Post-laboratory student- centered computer-based activity with discussion

The scaffold...

• Interactive Excel spreadsheet– Graphical analysis and interpretation – Quantitative symbolic relationships (P-V-T-n)– Influence of error

• html document with animations– pdf printable version as handout– Microscopic aspects incorporated using

Odyssey® converted to Flash files and NetLogo Java applet

– Dropdown menu with selected numerical answers

The Ideal Gas Law

Link to web activity

Outcomes for students...

• Many experimental observations and predictions

• Relating macroscopic and microscopic behavior via animations

• Symbolic relationships derived• Many “what if” scenarios via

numerical experimentation• Effects of “constant variables” and

error

Student responses…

• Survey students on the use of the technology

• Pre- and post-assessment of concept understanding

For further information…• The complete activity online - click here

• Constructing an interactive Excel spreadsheet – click here

• Scott Sinex– ssinex@pgcc.edu– http://academic.pgcc.edu/~ssinex

• Barbara Gage– bgage@pgcc.edu– http://academic.pgcc.edu/~bgage