Adiabatic vs. Isothermal: Difference and Comparison

Adiabatic and isothermal are terms used in thermodynamics to describe different types of processes based on how they handle heat. An adiabatic process refers to scenarios where no heat is exchanged between a system and its surroundings. This means that any change in the internal energy of the system is due solely to work done by or on the system. In contrast, isothermal processes occur at a constant temperature. This implies that heat can be transferred between the system and its surroundings, but the overall temperature remains unchanged.

For instance, consider a gas enclosed in a piston. If this gas is compressed quickly without allowing it to exchange heat with its environment, it would be an adiabatic process. The temperature of the gas might rise, but no heat is gained or lost from the system. On the other hand, if the gas is compressed slowly while maintaining a constant temperature by allowing heat exchange, it undergoes an isothermal process.

One notable outcome of an adiabatic process is the adiabatic flame temperature. It is the temperature achieved when a fuel is burned without any heat being lost to the surroundings. The concept contrasts with isothermal scenarios where processes, such as chemical reactions, can proceed while maintaining a constant temperature by either absorbing or releasing heat.

In summary, the distinction between adiabatic and isothermal lies in how they interact with heat. Adiabatic processes don't exchange heat, leading to changes in temperature based on the work done. Isothermal processes, while exchanging heat, maintain a constant temperature throughout.

A process without heat exchange.

A process at constant temperature.

A condition with no heat gain or loss.

Describes systems maintaining their temperature during processes.

Referring to changes in temperature without heat transfer.

Referring to uniform temperature throughout.

Thermodynamic changes solely due to work.

Thermodynamic changes with heat transfer maintaining temperature.

Describes a system isolated from heat exchange.

A condition where temperature doesn't change despite heat exchange.

Of, relating to, or being a reversible thermodynamic process that occurs without gain or loss of heat and without a change in entropy.

Of, relating to, or indicating equal or constant temperatures.

That occurs without gain or loss of heat (and thus with no change in entropy, in the quasistatic approximation).

Of or designating changes of pressure and volume at constant temperature.

That involves the slow change of the Hamiltonian of a system from its initial value to a final value.

Of or relating to an isotherm.

An adiabatic curve or graph

An isotherm.

Not giving out or receiving heat.

Of or pertaining to a process that takes place at constant temperature

occurring without loss or gain of heat;

Of or pertaining to an isotherm

(geography) An isotherm

Relating to equality of temperature, or an isotherm.

of a process or change taking place at constant temperature

Yes, as the water maintains a constant temperature during boiling.

It generally increases due to the work done on the gas.

It refers to processes without heat exchange.

By allowing heat exchange with the surroundings.

It represents the maximum temperature a fuel can achieve when burned without heat loss.

Not always, but rapid processes often tend toward adiabatic conditions due to limited time for heat exchange.

Yes, temperature can change in adiabatic processes due to work.

Rarely, as real-world scenarios often have some heat loss or gain.

By using controlled environments like water baths to maintain temperature.

In adiabatic, energy changes are due to work, while isothermal can involve both heat and work.