Intro to Thermal Processes Video Lessons

Concept

# Problem: An ideal monatomic gas is contained in a cylinder with a movable piston so that the gas can do work on the outside world, and heat can be added or removed as necessary. The figure shows various paths that the gas might take in expanding from an initial state whose pressure, volume, and temperature are , , and  respectively. The gas expands to a state with final volume . For some answers it will be convenient to generalize your results by using the variable , which is the ratio of final to initial volumes (equal to 4 for the expansions shown in the figure.)The figure shows several possible paths of the system in the pV plane. Although there are an infinite number of paths possible, several of those shown are special because one of their state variables remains constant during the expansion. These have the following names:Adiabiatic: No heat is added or removed during the expansion.Isobaric: The pressure remains constant during the expansion.Isothermal: The temperature remains constant during the expansion.Part AWhat happens to the temperature of the gas during an isobaric expansion?a) Temperature increases.b) Temperature remains constant.c) Temperature decreases.

###### FREE Expert Solution

Part A

During the isobaric expansion:

K = V/T

The volume of the gas, V, is directly proportional to its temperature, K.

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###### Problem Details

An ideal monatomic gas is contained in a cylinder with a movable piston so that the gas can do work on the outside world, and heat can be added or removed as necessary. The figure shows various paths that the gas might take in expanding from an initial state whose pressure, volume, and temperature are , , and  respectively. The gas expands to a state with final volume . For some answers it will be convenient to generalize your results by using the variable , which is the ratio of final to initial volumes (equal to 4 for the expansions shown in the figure.)

The figure shows several possible paths of the system in the pV plane. Although there are an infinite number of paths possible, several of those shown are special because one of their state variables remains constant during the expansion. These have the following names:

• Isobaric: The pressure remains constant during the expansion.
• Isothermal: The temperature remains constant during the expansion.

Part A

What happens to the temperature of the gas during an isobaric expansion?

a) Temperature increases.

b) Temperature remains constant.

c) Temperature decreases.