Equation of state for ideal gases with Cobra4 (gas laws: Gay-Lussac, Amontons, Boyle)

Principle

The state of a gas is determined by temperature, pressure and amount of substance. For the limiting case of ideal gases, these state variables are linked via the general equation of state. For a change of state under isochoric conditions this equation becomes Amontons' law. In this experiment it is investigated whether Amontons' law is valid for a constant amount of gas (air).

Benefits

• Unique system: All gas laws can be measured with the same setup
• Very compact setup, can be stored in the shelf and is always ready to use
• Very demonstrative: Volume is read directly at the gas syringe, temperature and pressure are measured with sensors in real-time
• Heating system is integrated in experiment setup
• Direct and versatile measurement with Cobra4 Mobile-Link: Measurement values visible on display (lab experiment/ student experiment), or connect it with a computer via USB-cable (direct measurement of a diagram, in combination with a projector as teacher demonstration), or add the Cobra4 Display-Connect module to connect it wirelessly to a digital large scale display

Tasks

• For a constant amount of gas (air) investigate the correlation of

1. Volume and pressure at constant temperature (Boyle and Mariotte's law)
2. Volume and temperature at constant pressure (Gay-Lussac's law)
3. Pressue and temperature at constant volume (Charles' (Amontons' law))

• From the relationships obtained calculate the universal gas constant as well as the coefficient of thermal expansion, the coefficient of thermal tension, and the coefficient of cubic compressibility.
  

What you can learn about

• Thermal tension coefficient
• General equation of state for ideal gases
• Universal gas constant
• Amontons' law

Software included. Computer not provided.