What happens when chemical compounds are added to water?

Submitted by Barbara Reisner / James Madison University on Sat, 11/17/2007 - 18:38
Description

It’s very surprising how little students remember from general chemistry.  This assignment helps students make connections between the macroscopic properties of solutions and what happens at the molecular level.  This activity serves as a bridge between sections on acid-base chemistry and coordination chemistry.

Students are solicited for their models of the behavior of different chemical compounds in water in class and asked to put these models on the board.  We then look at the properties of these solutions (color, acid-base) and refine these models in class.

Looking at Solid State Structures

Submitted by Barbara Reisner / James Madison University on Sat, 11/17/2007 - 18:05
Description

I find that students get a better understanding of solid state structure by playing with models.  I give students two fifty-minute class periods to look at the structure types that we discuss in class.  This is an old in-class activity that needs massive updating.

In this activity,  students look at the holes in different lattice types (simple cubic, ccp, hcp) and the CsCl, NaCl, CdI2, ZnS, and spinel structure types.

Determining Molecular Structure: An Experimental Simulation of X-ray Diffraction

Submitted by Maggie Geselbracht / Reed College on Sat, 11/17/2007 - 16:53
Description
­This activity introduces students to the symmetries of 2-D repeating patterns and X-ray diffraction. Using small lasers and Optical Transform slides (available from the Institute for Chemical Education), students qualitatively and quantitatively investigate the relationships between the sizes and symmetries of unit cells and the effects observed in diffraction patterns.