first-year undergraduate

Using My Marbles: Connecting Surface Area and Calorimetry with Temperature Curves and Thermochromic Cups

The importance of surface area can be illustrated by adding spherical solids at known sizes and temperature to other substances at different temperatures and then monitoring the rates of temperature changes of the system over time. Larger spheres (with less surface area per sample) exchanged heat with water more slowly than smaller spheres, and less thermally conductive glass spheres exchanged heat with water more slowly than iron spheres. Additional, more colorful demonstrations are described in which small glass spheres cool thermochromic plastic cups more quickly than larger glass spheres. 

Seawater Chemistry and Global Trade: Part 4

Continuation of the practical application of chemistry to seemingly something unrelated- global maritime trade. In this classroom activity students predict the buoyancy (and hence stability) of a merchant cargo ship based on interpretation of seawater surface salinity values. Like in the first three posts, the question types are conceptual. 

Seawater Chemistry and Global Trade: Part 3

This is the third post in a series dealing with seawater chemistry and global maritime trade. This classroom activity introduces the concept of salinity and tasks students to predict the range of salinities in certain regions of the ocean (coastal and open water, all four hemispheres, high and lower latitudes). Enjoy...

Too Hot to Handle? Hydrogen Reacts with Oxygen on Palladium Foil

The reaction of hydrogen and oxygen gases to form water is well known to be an exothermic reaction. That reaction can occur by first absorbing the hydrogen into palladium metal, and then placing the resulting palladium hydride into contact with oxygen in the air. Infrared and visible light videos were recorded for this process involving palladium foil, and the Green Chemistry and safety aspects of these activities are considered.