Skip to main content
Ch.18 - Thermodynamics: Entropy, Free Energy & Equilibrium
McMurry - Chemistry 8th Edition
McMurry8th EditionChemistryISBN: 9781292336145Non è quello che usi tu?Cambia libro di testo
Capitolo 18, Problema 57d

Which state in each of the following pairs has the higher entropy per mole of substance? (d) Water vapor at 150 °C and 1 atm or water vapor at 100 °C and 2 atm

Guida verificata passo dopo passo
1
Entropy is a measure of the disorder or randomness in a system. In general, the higher the temperature and the lower the pressure, the higher the entropy.
Consider the effect of temperature: Higher temperature increases the kinetic energy of molecules, leading to greater disorder. Therefore, water vapor at 150 °C will have higher entropy than at 100 °C.
Consider the effect of pressure: Lower pressure allows molecules to spread out more, increasing disorder. Therefore, water vapor at 1 atm will have higher entropy than at 2 atm.
Compare the two conditions: Water vapor at 150 °C and 1 atm has both higher temperature and lower pressure compared to water vapor at 100 °C and 2 atm.
Conclude that water vapor at 150 °C and 1 atm has higher entropy per mole than water vapor at 100 °C and 2 atm.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
4m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Entropy

Entropy is a measure of the disorder or randomness in a system. In thermodynamics, it quantifies the number of microscopic configurations that correspond to a thermodynamic system's macroscopic state. Higher entropy indicates greater disorder and more available microstates, which is often associated with gases compared to liquids or solids.
Video consigliato:
Percorso guidato
02:46
Entropy in Thermodynamics

Effect of Temperature on Entropy

Temperature significantly influences entropy; as temperature increases, the kinetic energy of particles also increases, leading to greater molecular motion and disorder. Therefore, at higher temperatures, substances generally exhibit higher entropy due to the increased number of accessible energy states for the molecules.
Video consigliato:
Percorso guidato
02:35
Entropy and Physical Changes

Effect of Pressure on Entropy

Pressure affects the entropy of gases, as increasing pressure typically reduces the volume available to gas molecules, thereby limiting their freedom of movement and reducing disorder. However, at constant temperature, a gas at lower pressure can have higher entropy than at higher pressure, especially if the temperature is also considered.
Video consigliato:
Percorso guidato
02:35
Entropy and Physical Changes