Real Chemistry that's Practically NO COST (updated March 23, 2003)

WebElements Periodic Table of the Elements

Virtual Chemistry from Davidson College. Scroll to "Topics"

scroll to "chemistry applets" to learn to use different instruments BEFORE you go hands-on

Virtual Chemistry from Oxford Metal ions in solution

Atoms and Molecules

• Atomic Cookies (word document) Use toothpicks for bonds to build non-planar molecules.
• Pla-Do recipes
  • http://northpole.net/crafts/xmasdough.htm
  • http://www.cpinternet.com/~sarah/rdr010.html
  • http://www.netcooks.com/recipes/Kids/Playdough.html

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Light Transmission or absorption--effect of path length

A wide variety of substances absorb (or transmit) light. Some (pigments) absorb light in the visible range of the spectrum. Others (like DNA and protein) absorb light in the Ultraviolet range. Hemoglobin contains a pigment, heme, which makes the protein red. Beer's Law describes how how intrinsic properties of the substance, its concentration and the path length of the light coming through all affect how much light is absorbed or transmitted. A spectrophotometer (colorimeter) is a device/instrument that can detect light absorbed at different wavelengths. You can see the same phenomenon in a qualitative way by using an overhead projector as the light source and the screen as the detector.

Materials

• overhead projector
• colored water (keep it pale but visibly colored for the best effect)
• beakers
• multiwell plate
• overhead sheet with different colors
• black paper to block light
• white paper to enhance contrast

1. Pour some liquid into a beaker.
2. Pour another volume of the very same liquid
3. Note what happens
4. Continue pouring and note what happens
5. Ask students to come around and view the beaker from the side

Have students explain the difference when viewed through the overhead or from the side.

Polymers

Life's polymer: DNA

What the DNA isolation process looks like (You have to do it and enjoy it yourself!)

Crystal Structure

Examples of crystals (minerals)

Applets of crystal structures (takes time to load). You can change parameters.

Light diffraction gives clues to crystal structure

Diffusion

Materials:

• food coloring
• paper towels
• coffee filters
• dropper
• water, ethyl rubbing alcohol
• isopropyl rubbing alcohol
• dropper
• plastic wrap or overhead plastic
• Petri plate

Each group gets a different food color.

1. Apply a drop of each food coloring on each type of paper.
2. Allow to dry.
3. Slowly and carefully, drop water or alcohol on the drop of dye

Make a table with these headings: paper type, dye color (and # of drops), solvent (and # of drops). Note ALL observations. Draw the patterns. Visit another team (with the same or differnet dye) and see how you patterns compare and contrast. Note these differences.

Chemical Equilibria

Polarization of light by chiral chemical compounds

• History
• In Scientific American
• What is chirality?
• Polarizing light in photography
• Optical activity of Karo syrup
• Polarized light used to check purity of sugar for importation
• Chirality and the origin of life

What's a Mole?

• MoleMath
• Thinking about Moles
• Celebrate Mole Day and here
• Mole pedagogy
• Student artwork depicting a mole
• Moles and Molarity/Concentration and Amount

In the lab

Vapor Pressure and Evaporation

Chemistry Club

General Chemistry CURI Modules

Questions? Comments? Suggestions?

Developed by Dr. Toby Horn for my colleague DC ACTS teachers