Skip to main content
Ch.18 - Free Energy and Thermodynamics
Tro - Chemistry: A Molecular Approach 4th Edition
Tro4th EditionChemistry: A Molecular ApproachISBN: 9780134112831Non è quello che usi tu?Cambia libro di testo
Tutti i libri di testoTro 4th EditionCh.18 - Free Energy and ThermodynamicsProblema 89c
Capitolo 18, Problema 89c

Consider this reaction occurring at 298 K: N2O(g) + NO2(g) ⇌ 3 NO(g) c. Can the reaction be made more spontaneous by an increase or decrease in temperature? If so, what temperature is required to make the reaction spontaneous under standard conditions?

Guida verificata passo dopo passo
1
insert step 1> Determine the standard enthalpy change (\( \Delta H^\circ \)) and standard entropy change (\( \Delta S^\circ \)) for the reaction using standard thermodynamic tables.
insert step 2> Use the Gibbs free energy equation \( \Delta G^\circ = \Delta H^\circ - T \Delta S^\circ \) to find the standard Gibbs free energy change (\( \Delta G^\circ \)) at 298 K.
insert step 3> Determine if the reaction is spontaneous at 298 K by checking if \( \Delta G^\circ < 0 \).
insert step 4> To find the temperature at which the reaction becomes spontaneous, set \( \Delta G^\circ = 0 \) and solve for temperature \( T \) using the equation \( T = \frac{\Delta H^\circ}{\Delta S^\circ} \).
insert step 5> Analyze whether increasing or decreasing the temperature will make the reaction more spontaneous based on the signs of \( \Delta H^\circ \) and \( \Delta S^\circ \).

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:
8m

Concetti chiave

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

Gibbs Free Energy

Gibbs Free Energy (G) is a thermodynamic potential that helps predict the spontaneity of a reaction at constant temperature and pressure. A reaction is spontaneous if the change in Gibbs Free Energy (ΔG) is negative. The relationship between ΔG, enthalpy (ΔH), and entropy (ΔS) is given by the equation ΔG = ΔH - TΔS, where T is the temperature in Kelvin.
Video consigliato:
Percorso guidato
01:51
Gibbs Free Energy of Reactions

Entropy and Enthalpy

Entropy (S) is a measure of the disorder or randomness in a system, while enthalpy (H) is a measure of the total energy of a system, including internal energy and the energy required to make room for it. For a reaction to be spontaneous, the increase in entropy must outweigh the enthalpy changes, particularly at higher temperatures, where the TΔS term becomes significant in the Gibbs Free Energy equation.
Video consigliato:
Percorso guidato
02:46
Entropy in Thermodynamics

Temperature's Effect on Spontaneity

The temperature of a system can significantly influence the spontaneity of a reaction. If a reaction has a positive ΔS (increase in entropy), increasing the temperature can make the reaction more spontaneous by lowering ΔG. Conversely, if ΔH is positive (endothermic reaction), a higher temperature may be required to achieve a negative ΔG, thus making the reaction spontaneous under standard conditions.
Video consigliato:
Percorso guidato
01:17
Spontaneity and Temperature
Pratica correlata
Domanda del libro di testo

Consider this reaction occurring at 298 K: N2O(g) + NO2(g) ⇌ 3 NO(g) a. Show that the reaction is not spontaneous under standard conditions by calculating ΔG°rxn.

1400
views
Domanda del libro di testo

Consider this reaction occurring at 298 K: N2O(g) + NO2(g) ⇌ 3 NO(g) b. If a reaction mixture contains only N2O and NO2 at partial pressures of 1.0 atm each, the reaction will be spontaneous until some NO forms in the mixture. What maximum partial pressure of NO builds up before the reaction ceases to be spontaneous?

1806
views
Domanda del libro di testo

Consider this reaction occurring at 298 K: BaCO3(s) ⇌ BaO(s) + CO2( g) b. If BaCO3 is placed in an evacuated flask, what is the partial pressure of CO2 when the reaction reaches equilibrium?

1693
views
Domanda del libro di testo

Consider this reaction occurring at 298 K: BaCO3(s) ⇌ BaO(s) + CO2(g) a. Show that the reaction is not spontaneous under standard conditions by calculating ΔG°rxn.

391
views
Domanda del libro di testo

Consider this reaction occurring at 298 K: BaCO3(s) ⇌ BaO(s) + CO2(g) c. Can the reaction be made more spontaneous by an increase or decrease in temperature? If so, at what temperature is the partial pressure of carbon dioxide 1.0 atm?

1004
views