Specific Heat Capacity

• Turn on the heat to see how much heat is needed to change the temperature of the sample by $1K$.
• The power of the heat source is $100W = 100J/s$.
• $Q$ is given by the power input of the heat source times $t$.
• Drag the coordinate tool (the hollow square box) to make measurements on the graph.

Phase Transition of Water

• Turn on the heat to observe phase transition. You can zoom in and out of the graph with the buttons.
• The power of the heat source is $50kW = 50kJ/s$.
• $Q$ is given by the power input of the heat source times $t$.
• Observe that the liquid-gas phase transition take a lot longer than the solid-liquid transition. Can you explain why?
• Specific heat capacity of ice, water, steam: $2.1kJ/kg^{-1}K^{-1}$, $4.186kJ/kg^{-1}K^{-1}$, $2kJ/kg^{-1}K^{-1}$.
• Latent heat of fusion and vaporization: $334kJ/kg$, $2254kJ/kg$
• The above values are approximations only. True values are temperature dependent, and also depend the heating process (e.g. isobaric vs isochoric).

Ideal Gas at Constant Temperature

Drag the piston to change the volume isothermally. The heat bath exchanges heat with the gas to keep it at constant temperature.

Adiabatic Change

Click on the "adiabatic" button to add thermal insulation to prevent heat exchange. Observe how the tempertaure changes with volume. A few background isothermal curves at $200K$ interval are included for reference.

Things to try:
• By switching back and forth between isothermal and adiabatic processes, raise the temperature to above $1500K$ by moving the piston alone. Don't touch the temperature slider.
• Similarly, try to lower the temperature to below $200K$ by moving the piston.

Ideal Gas at Constant Pressure or Volume (isobaric and isochoric processes)

• Turn on the heat or cold to change the pressure or the volume.
• Switch among P vs V, T vs V, and P vs T graphs.
• The power of the heat source is $500W = 500J/s$.
• $Q$ is given by the power input of the heat source times $t$.

Heat Capacity at Constant Pressure or Volume

A lab manual based on this simulation is available here.

• Turn on the heat and observe the change in temperature.
• The heat capacity of a gas depends on how the heating process takes place.
• At constant pressure (isobaric), the total heat capacity for an ideal gas is $C_P = (\frac{f}{2}+1)nR$.
• At constant volume (isochoric), the total heat capacity is $C_V = \frac{f}{2}nR$.
• $Q$ is given by the power input of the heat source times $t$.

Virtual lab:
• Drag the coordinate tool (the hollow square box) to make measurements on the graph.
• Heat the gas under isobaric and isochoric conditions and use the graphs to calculate the heat capacities.
• Change $n$ and $f$ and measure the effects on the heat capacities.
• Heat the gas to the same final temperature under isobaric and isochoric conditions. Measure the difference in the total heat input $Q$ for the two cases. Use the work done by the gas during the processes to quantitatively account for the difference.