Observing Latent Heat With a Portable Hand Warmer

Students conduct a series of investigation on latent heat of fusion. In this chemistry lesson, students explain how thermal storage systems work. They draw and interpret graphs.

Clever! Use a clip from the 1997 film, Volcano, to get your chemistry class knee-deep in heat concepts related to lava. In the movie scene, lava flow is stopped in the nick of time. Your class must use calculations to determine if this...

How does heat move from one item to another, even when the items are in different states of matter? Pupils experiment with adding washers to hot water and adding hot washers to room temperature water to observe the heat transfer. 

Where does the heat come from in hand warmers? Learn about enthalpy, the change in energy in a system, to see that when chemical bonds are broken or formed, energy moves into and out of a system because of chemical reactions. 

When the chemists who designed hand warmers were working, they had to consider how much heat they could give off to keep people warm  — and not burn anyone in the process. How is this heat given off in a chemical reaction measured?...

How can heat power an engine? Scholars observe a heat engine working and control variables to determine the most efficient setup. They change the amount of heat input as well as the stroke length. Energy efficiency numbers prove the...

There's more to melting than meets the eye! Junior physical chemists investigate the differences between specific and latent heats as a substance undergoes a phase change. Users remove heat from the system and observe changes in kinetic...

Scholars learn about heat release in phase changes. They perform calculations as they compare and contrast a science fiction passage and a home heating application.

What happens inside a melting solid? Prospective physical chemists observe a solid-to-liquid phase change at the molecular level using an inspired interactive. Pupils add heat to a close system, then monitor changes in kinetic and...

Hot cocoa is easy to make with only two ingredients, so what does it have to do with chemistry? The lesson begins with what seems like an obvious question. Then scholars perform simulations to focus on phase changes. Lastly, they...