- Energy changes during reactions
Neat animation showing how bond making and breaking relates to activation energy, and whether a reaction is endothermic or exothermic. YouTube
- An exothermic reaction - sodium and chlorine
The exothermic reaction between sodium and chlorine. YouTube
- An exothermic reaction - iron and sulfur
This shows the reaction between sulfur and iron wool to make iron(II) sulfide. This reaction is normally done by heating a mixture of sulfur and iron filings, but this is much more spectacular. As well as heat and light, energy is also released as sound. YouTube
- An exothermic reaction - the thermite reaction
A quite long (almost 6 minutes) lecture demonstration from Bob Burk. It uses the thermite reaction and the rusting of iron to illustrate the fact that you can't tell how exothermic a reaction is just by looking at it. Good stuff! YouTube
- Heating copper(II) carbonate
The effects of heat on carbonates are classic endothermic changes. This very short clip shows the effect of heating copper(II) carbonate, and tests for the carbon dioxide evolved using lime water. Notice the change from the green copper(II) carbonate to black copper(II) oxide. YouTube