Physics · Heat and Thermodynamics
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A monatomic ideal gas is thermally insulated, so no heat can flow between it and its surroundings. Is it possible for the temperature of the gas to rise?
- A
Yes. The temperature can rise if work is done by the gas.
- B
No. The only way that the temperature can rise is if heat is added to the gas.
- C
Yes. The temperature can rise if the work is done on the gas.
- D
No. The only way that the temperature can rise is by adding more molecules in container.
In a thermally insulated system, where no heat can flow between the gas and its surroundings, the change in internal energy of the gas is solely determined by the work done on or by the gas and not by heat transfer.
If work is done on the gas, such as compressing the gas or applying external forces to it, the gas can gain energy. This increase in energy corresponds to an increase in temperature. The work done on the gas increases the kinetic energy of its molecules, leading to a rise in temperature.
This option suggests that the temperature of the gas can rise if work is done by the gas. According to the first law of thermodynamics, the change in internal energy (ΔU) of a system is equal to the heat added to the system (Q) minus the work done by the system (W): ΔU=Q−W. If work is done by the gas (W is positive), the internal energy of the gas decreases, which could result in a decrease in temperature.
This option suggests that the only way for the temperature of the gas to rise is by adding heat to the gas. This statement is generally correct. According to the ideal gas law, when heat is added to a gas at constant volume, its temperature increases. However, if the gas is thermally insulated, no heat can flow into or out of the gas, so the temperature cannot increase.
In a thermally insulated system, where no heat can flow between the gas and its surroundings, the change in internal energy of the gas is solely determined by the work done on or by the gas and not by heat transfer.
If work is done on the gas, such as compressing the gas or applying external forces to it, the gas can gain energy. This increase in energy corresponds to an increase in temperature. The work done on the gas increases the kinetic energy of its molecules, leading to a rise in temperature.
This option suggests that the only way for the temperature of the gas to rise is by adding more molecules to the container. While adding more molecules to a gas can increase its temperature under certain conditions (such as constant volume), in the scenario described (thermally insulated), the number of molecules in the container remains constant. Therefore, this option is not applicable in this context.
Tagged under Physics · Heat and Thermodynamics · 2021