What is the entropy change when 2 moles of an ideal gas are compressed isothermally from volume V2 to V1?
Practice Questions
1 question
Q1
What is the entropy change when 2 moles of an ideal gas are compressed isothermally from volume V2 to V1?
-R ln(V1/V2)
R ln(V1/V2)
0
R (V2 - V1)
The change in entropy for an isothermal compression is ΔS = nR ln(V1/V2). For 2 moles, ΔS = 2R ln(V1/V2), which is negative since V1 < V2.
Questions & Step-by-step Solutions
1 item
Q
Q: What is the entropy change when 2 moles of an ideal gas are compressed isothermally from volume V2 to V1?
Solution: The change in entropy for an isothermal compression is ΔS = nR ln(V1/V2). For 2 moles, ΔS = 2R ln(V1/V2), which is negative since V1 < V2.
Steps: 6
Step 1: Understand that we are dealing with an ideal gas and the process is isothermal, meaning the temperature remains constant.
Step 2: Recall the formula for the change in entropy (ΔS) during an isothermal process: ΔS = nR ln(V1/V2).
Step 3: Identify the variables: n is the number of moles (which is 2), R is the ideal gas constant, V1 is the final volume, and V2 is the initial volume.
Step 4: Substitute the number of moles into the formula: ΔS = 2R ln(V1/V2).
Step 5: Recognize that since V1 is less than V2 (the gas is being compressed), the value of ln(V1/V2) will be negative.
Step 6: Conclude that the change in entropy (ΔS) will also be negative, indicating a decrease in entropy due to the compression.
