Experiment Experiment: Latent Heat of Vaporization of Water

Topics covered:

- Latent heat of state change

- Thermal equilibrium

- Energy transformation

- Efficiency

Principles and objectives:

A mass of water Mwater is introduced into the calorimeter equipped with a temperature probe and placed on a scale.

This water is heated using the calorimeter's resistance, whose power is measured by a voltmeter sensor

and an ammeter sensor.

The temperature increases and stabilizes at the evaporation temperature (100°C), a significant mass of water M100°C (determined by the scale) is allowed to evaporate over a time interval t100°C. The efficiency μ of the heating system is determined from the U, I, and T curves in the temperature rise section of Mwater

(before reaching 100°C) from T1 to T2 in t1→2

The latent heat of vaporization of water is then calculated: Qm100°C = μ U I t100°C

Comments:

The use of the ExAO Foxy range and the Atelier scientifique software suite makes the implementation of these experiments attractive, in addition to simplifying the setup and ensuring measurement accuracy.

Other experiments are, of course, feasible with the same setups such as the heat of fusion of water, determining the calorimeter's thermal capacity, etc.

- 1 Calorimeter (ref 253081) - 1 Balance 3000g / 0.1g (ref 705010) - 1 Foxy 2 Console (ref 485000) - 1 A.S. Sup Software (ref 000131) - 1 Thermometer Sensor (ref 482101) - 1 TRMS Voltmeter Sensor (ref 482035) - 1 TRMS Ammeter (ref 482034) - 1 Adjustable Power Supply 30 V / 5 A (ref 281490) - 2 Safety Cables 100 cm Banana with 4mm Rear Recovery Black (ref 284842) - 3 Safety Cables 100 cm Banana with 4mm Rear Recovery Red (ref 284843)