Skip to main content
Ch.19 - Free Energy & Thermodynamics
Tro - Chemistry: A Molecular Approach 5th Edition
Tro5th EditionChemistry: A Molecular ApproachISBN: 9780134874371Non è quello che usi tu?Cambia libro di testo
Tutti i libri di testoTro 5th EditionCh.19 - Free Energy & ThermodynamicsProblema 31
Capitolo 19, Problema 31

Calculate the change in entropy that occurs in the system when 1.00 mole of isopropyl alcohol (C3H8O) melts at its melting point (-89.5 °C). See Table 12.9 for heats of fusion.

Guida verificata passo dopo passo
1
Identify the formula for calculating the change in entropy (\( \Delta S \)) during a phase change: \( \Delta S = \frac{q_{\text{rev}}}{T} \), where \( q_{\text{rev}} \) is the heat absorbed or released during the process and \( T \) is the temperature in Kelvin.
Determine the heat of fusion (\( \Delta H_{\text{fus}} \)) for isopropyl alcohol from Table 12.9. This value represents the amount of heat required to melt one mole of isopropyl alcohol at its melting point.
Convert the melting point from Celsius to Kelvin by adding 273.15 to the Celsius temperature: \( T = -89.5 + 273.15 \).
Substitute the values into the entropy change formula: \( \Delta S = \frac{\Delta H_{\text{fus}}}{T} \). Ensure that \( \Delta H_{\text{fus}} \) is in the same units as the temperature (usually Joules and Kelvin).
Calculate the change in entropy (\( \Delta S \)) using the values obtained in the previous steps.

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:
1m

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 amount of energy in a physical system that is not available to do work. When a substance changes state, such as melting, the entropy typically increases because the molecules move from a more ordered solid state to a less ordered liquid state.
Video consigliato:
Percorso guidato
02:46
Entropy in Thermodynamics

Heats of Fusion

The heat of fusion is the amount of energy required to change a substance from solid to liquid at its melting point without changing its temperature. This value is crucial for calculating the change in entropy during phase transitions, as it provides the necessary energy input to overcome intermolecular forces in the solid state.
Video consigliato:
Percorso guidato
02:19
Heat Capacity

Phase Change Calculations

Phase change calculations involve determining the energy changes associated with transitions between solid, liquid, and gas states. For melting, the change in entropy can be calculated using the formula ΔS = ΔH_fusion / T, where ΔH_fusion is the heat of fusion and T is the absolute temperature in Kelvin. This relationship is essential for understanding how energy and disorder change during phase transitions.
Video consigliato:
Percorso guidato
01:46
Entropy in Phase Changes
Pratica correlata
Domanda del libro di testo

Which of these processes are nonspontaneous? Are the nonspontaneous processes impossible? a. a bike going up a hill b. a meteor falling to Earth c. obtaining hydrogen gas from liquid water d. a ball rolling down a hill

1301
views
Domanda del libro di testo

Without doing any calculations, determine the sign of ΔSsys for each chemical reaction. a. 2 KClO3(s) → 2 KCl(s) + 3 O2(g) c. Na(s) + 2 Cl2(g) → NaCl(s) d. N2(g) + 3 H2(g) → 2 NH3(g)

3407
views
Domanda del libro di testo

Two systems, each composed of two particles represented by circles, have 20 J of total energy. Which system, A or B, has the greater entropy? Why?

418
views
Domanda del libro di testo

Calculate the change in entropy that occurs in the system when 1.00 mole of diethyl ether (C4H10O) condenses from a gas to a liquid at its normal boiling point (34.6 °C). See Table 11.7 for heats of vaporization.

2997
views
Domanda del libro di testo

Without doing any calculations, determine the sign of ΔSsys for each chemical reaction. b. CH2=CH2( g) + H2( g) → CH3CH3( g)

463
views
1
rank
Domanda del libro di testo

Two systems, each composed of three particles represented by circles, have 30 J of total energy. How many energetically equivalent ways can you distribute the particles in each system? Which system has greater entropy?

1463
views