Pyrophoric Lead

A pyrophoric lead is prepared by pyrolysis of lead(II) tartrate. It can ignite spontaneously in contact with air.

Materials
Test tube (16 mm x 160 mm), small spoon, metal tray with sand, burner, metal stand with clamp, matches.

Chemicals
Lead(II) tartrate

Fig. 1. Set up

Fig. 2. Burning of Lead

Experimental

• Add several small spoons of lead(II) tartrate in a test tube.
• Assemble apparatus as it is shown on the Fig.1 in a fume hood.
• Heat the test tube with a burner. Time after time rotate the test tube.
• When the whole amount of the substance turns black stop the heating.
• After cooling, in a fume hood, pour the content of the test tube on sand, in a metal tray as shown on Fig. 2.

Observation and Discussion

During the pyrolysis of lead(II) tartrate carbon and elemental lead are obtained in fine dispersed form.  In contact with air lead spontaneously ignites and spectacularly burns with sparks and smoke. Some of the reaction products can be seen in tray with sand.    

Safety Tips
The experiment must to be performed in a fume hood. The pyrolysis products are not healthy and the burning of lead produces a lead containing smoke which should not be inhale.