Thermodynamic Processes: Isobaric, Isochoric, Isothermal and Adiabatic process | Chemistry #12

Summary

This video explains four key thermodynamic processes: isobaric (constant pressure), isochoric (constant volume), isothermal (constant temperature), and adiabatic (no heat transfer). It discusses how these processes affect a system's parameters such as pressure, volume, temperature, and internal energy. The isobaric process involves work done due to changing volume at constant pressure. The isochoric process involves no work, only heat transfer affecting internal energy. In an isothermal process, temperature remains constant, with heat transferred as work. The adiabatic process occurs without heat exchange, with internal energy changing based on the work done.

Takeaways

• 😀 Thermodynamic processes describe how the state of a system changes, defined by parameters like pressure, temperature, volume, and internal energy.
• 😀 The state of a system can be changed by altering any of the system's parameters such as pressure or volume.
• 😀 An isobaric process keeps pressure constant while allowing volume to change. Work done in this process depends on the volume change.
• 😀 In an isochoric process, the volume of the system remains constant, so no work is done, and any heat added changes the internal energy.
• 😀 The isothermal process maintains constant temperature, and since temperature doesn't change, the internal energy remains constant as well.
• 😀 In an isothermal process, heat added to the system equals the work done by the system (Q = W).
• 😀 An adiabatic process involves no heat exchange between the system and surroundings (Q = 0), so any change in internal energy is due to work done on or by the system.
• 😀 In the adiabatic process, the change in internal energy equals the negative of the work done (ΔU = -W).
• 😀 Work done in an adiabatic process can increase or decrease the system’s internal energy depending on whether the system is expanding or compressing.
• 😀 The first law of thermodynamics links heat, work, and internal energy, governing the behavior of thermodynamic processes.
• 😀 By understanding these processes (isobaric, isochoric, isothermal, and adiabatic), we can predict how energy is transferred and work is performed in a system.

Q & A

What are the four main thermodynamic processes discussed in the video?

The four main thermodynamic processes discussed are isobaric, isochoric, isothermal, and adiabatic processes.

What happens during an isobaric process?

In an isobaric process, pressure is kept constant, and as a result, the volume of the system changes. Work done is calculated by the equation W = P × (V_final - V_initial).

How is work calculated in an isobaric process?

Work done in an isobaric process is calculated using the equation W = P × (V_final - V_initial), where P is the constant pressure, and V_final and V_initial are the final and initial volumes, respectively.

What does it mean if the work done in an isobaric process is positive or negative?

If the work done is positive, it indicates an expansion of the system, whereas if the work done is negative, it indicates a contraction of the system.

What is the defining characteristic of an isochoric process?

In an isochoric process, the volume of the system remains constant, meaning no work is done by the system.

Why is no work done in an isochoric process?

No work is done in an isochoric process because the volume of the system does not change. Work is only done when there is a change in volume.

What happens in an isothermal process?

In an isothermal process, the temperature of the system remains constant. Heat exchange occurs with an external thermal reservoir, and the system adjusts slowly to maintain temperature equilibrium.

What is the relationship between heat and work in an isothermal process?

In an isothermal process, since the temperature is constant, the change in internal energy is zero. Therefore, from the first law of thermodynamics, the heat transfer (Q) is equal to the work done (W).

What occurs during an adiabatic process?

In an adiabatic process, there is no heat exchange between the system and its surroundings (Q = 0). The change in internal energy is equal to the negative work done by or on the system.

How does work affect internal energy in an adiabatic process?

In an adiabatic process, the change in internal energy is equal to the negative of the work done. If the work done is negative (i.e., compression), the internal energy increases. If the work done is positive (i.e., expansion), the internal energy decreases.

What is the first law of thermodynamics, and how is it applied in the video?

The first law of thermodynamics states that the change in internal energy (ΔU) is equal to the heat added to the system (Q) minus the work done by the system (W). It is applied in each process to relate heat transfer and work done, showing how they influence internal energy.