Heat capacity of gases with Cobra4
Principle
Heat is added to a gas in a glass vessel by an electric heater which is switched on briefly. The temperature increase results in a pressure increase, which is measured with a manometer. Under isobaric conditions a temperature increase results in a volume dilatation, which can be read from a gas syringe. The molar heat capacities are calculated from the pressure or volume change.
Benefits
- Determination of cp and cv
- For both demonstration and student experiments
- Suitable for many different gases
- Simplified implementation: all pre-settings already prepared
Cobra4 Wireless/USB-Link incl. USB cable
Cobra4 Sensor-Unit Energy: Current, voltage, work, power
Stopcock,1-way,straight, glass
Stopcock,3-way,t-sh.,capil.,glass
Rubber stopper 26/32, 3 holes 7 mm + 2 x 1,5 mm
Rub.stop.d=59.5/50.5mm, 1 hole
Rubber tubing, i.d. 6 mm
Silicone tubing, inner diameter 3 mm
Nickel electrode,d 3mm,w.socket
Tubing adaptor, ID 3-5/6-10 mm
Scissors,straight,blunt,l 140mm
Weather monitor, 6 lines LCD
Tripod base PHYWE
Syringe 10ml, Luer, 10 pcs
Mariotte flask, 10 l
Precision manometer
On/off switch
Chrome-nickel wire, d.0,1mm,100m
Connecting cord, 32 A, 250 mm, blue
Connecting cord, 32 A, 500 mm, red
Connecting cord, 32 A, 500 mm, blue
curricuLAB measureLAB
PHYWE power supply, 230 V, DC: 0…12 V, 2 A / AC: 6 V, 12 V, 5 A
Tasks
Determine the molar heat capacities of air at constant volume and at constant pressure.
What you can learn about
• Equation of state for ideal gases
• 1st law of thermodynamics
• Universal gas constant
• Degree of freedom
• Mole volumes
• Isobars
• Isotherms
• Isochors and adiabatic changes of state