Arco® Hope’s Apparatus

Demonstrates water's maximum density at 4 °C.

• Cylindrical metal vessel with annular trough

  Fitted with tubulures for thermometers and stoppers

Hope's apparatus is used to show that water reaches maximum density at 4 °C, illustrating anomalous expansion behavior. Simply fit two thermometers into the tubulures with the rubber stoppers, fill the metal vessel with water, and fill the annular trough with ice. The ice will cool the water in the vessel to 0 °C where it contacts the trough, but the bottom thermometer - where the highest density water settles - will read 4 °C. Students will undetrstand that, though density of a liquid changes with temperature, the special properties of water create an interesting anomaly.

Delivery information: Includes (1) cylindrical vessel with trough, (2) thermometer tubulures.