The Mercury Beating Heart is a popular chemistry demonstration or experiment in which a blob of mercury is made to pulsate, resembling a beating heart. The mercury beating heart requires only a few materials and is easy to set up, though it's a little tricky to get going.
Mercury Beating Heart Materials
- drop of mercury
- dilute sulfuric acid (battery acid strength works)
- potassium permanganate or potassium dichromate solution or crystals
- iron wire or nail
- watch glass or petri dish
Perform the Mercury Beating Heart Demonstration
- Place a drop of mercury into a dish.
- Cover the mercury with sulfuric acid.
- Add a small amount of potassium permanganate or potassium dichromate.
- Slowly move the iron wire or nail so that the tip is near the mercury, but not quite touching it. The distance depends on the ratio of the concentration of the acid and oxidizer, so you'll need to play with this to find the sweet spot.
- Once you have the distance right, the mercury will contract into a rounded ball and then spread out to touch the iron and contract again. The 'beating heart' will beat for about 20 seconds.