Doing work on a gas always implies

Answer

a. adding internal energy.

b. adding heat.

c. changing the volume.

d. adding potential.

To determine the correct answer, we need to understand the concepts related to the work done on a gas.

Work is defined as the transfer of energy that occurs when a force is applied to an object, causing it to move. In the case of a gas, work is done when the gas undergoes a change in volume as a result of an applied force.

According to the definition of work, the correct answer is:

c. changing the volume.

When work is done on a gas, it means that an external force has been applied to the gas causing it to change volume. This can be done by compressing or expanding the gas, which requires the application of a force to overcome the pressure inside the gas. This work increases or decreases the internal energy of the gas.

Options a and d, adding internal energy and adding potential, are incorrect because work is not directly related to internal energy or the addition of potential energy in the context of a gas system.

Option b, adding heat, is also incorrect. Adding heat to a gas does not necessarily imply doing work. Heat is a form of energy transfer, while work involves the transfer of mechanical energy.

Therefore, the correct answer is c. changing the volume.