solutions

A Cool Drink!: An Introduction to Concentrations

In this Activity, students investigate concentration levels by using serial dilution to prepare several solutions of presweetened powdered drink mix. Students taste the solutions to determine at which concentration they first discern the sweetness. A connection is also made to the concentration of pollutants in air.

Popcorn: What's in the Bag?

In this Activity, students investigate microwave popcorn, the process of microwave-promoted popping, and the materials involved: water, vegetable oils, starch, and special packaging materials. This Activity supports discussion of thermal and electromagnetic energy, phase changes, intermolecular forces, patterns of solubility, and the structure of fats, oils and starches.

Diffusion of Water through a Differentially Permeable Membrane

In this Activity, students investigate the process of osmosis through a differentially-permeable membrane formed by the precipitation of copper(II) hexacyanoferrate(II). This Activity allows students to watch and investigate osmosis, which reinforces the concept of transport in living cells.