Domanda del libro di testo
Tell whether the free-energy changes, ΔG, for the processes listed in Problem 9.127 are likely to be positive, negative, or zero.
241
views
Ch.9 - Thermochemistry: Chemical Energy
McMurry8th EditionChemistryISBN: 9781292336145
Non è quello che usi tu?Cambia libro di testoScegli un libro di testo diverso
TOC.tableOfContents
- Ch.1 - Chemical Tools: Experimentation & Measurement170
- Ch.2 - Atoms, Molecules & Ions160
- Ch.3 - Mass Relationships in Chemical Reactions169
- Ch.4 - Reactions in Aqueous Solution199
- Ch.5 - Periodicity & Electronic Structure of Atoms102
- Ch.6 - Ionic Compounds: Periodic Trends and Bonding Theory92
- Ch.7 - Covalent Bonding and Electron-Dot Structures61
- Ch.8 - Covalent Compounds: Bonding Theories and Molecular Structure59
- Ch.9 - Thermochemistry: Chemical Energy122
- Ch.10 - Gases: Their Properties & Behavior155
- Ch.11 - Liquids & Phase Changes54
- Ch.12 - Solids and Solid-State Materials73
- Ch.13 - Solutions & Their Properties120
- Ch.14 - Chemical Kinetics98
- Ch.15 - Chemical Equilibrium125
- Ch.16 - Aqueous Equilibria: Acids & Bases110
- Ch.17 - Applications of Aqueous Equilibria147
- Ch.18 - Thermodynamics: Entropy, Free Energy & Equilibrium86
- Ch.19 - Electrochemistry154
- Ch.20 - Nuclear Chemistry96
- Ch.21 - Transition Elements and Coordination Chemistry156
- Ch.22 - The Main Group Elements187
- Ch.23 - Organic and Biological Chemistry51
Capitolo 9, Problema 124
How is it possible for a reaction to be spontaneous yet endothermic?
Guida verificata passo dopo passo1
Understand that a spontaneous reaction is one that occurs without needing to be driven by an external force. It is determined by the change in Gibbs free energy (ΔG).
Recall the Gibbs free energy equation: ΔG = ΔH - TΔS, where ΔG is the change in free energy, ΔH is the change in enthalpy, T is the temperature in Kelvin, and ΔS is the change in entropy.
Recognize that for a reaction to be spontaneous, ΔG must be negative.
Consider that an endothermic reaction has a positive ΔH, meaning it absorbs heat from the surroundings.
Realize that if the increase in entropy (ΔS) is large enough and the temperature (T) is high enough, the TΔS term can outweigh the positive ΔH, resulting in a negative ΔG, thus making the reaction spontaneous.
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:
1mConcetti chiave
Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.
Spontaneity of Reactions
A reaction is considered spontaneous if it occurs without external intervention. This is often determined by the change in Gibbs free energy (ΔG); if ΔG is negative, the reaction is spontaneous. Spontaneity is influenced by both enthalpy (ΔH) and entropy (ΔS) changes during the reaction.
Video consigliato:
Percorso guidato
04:20
Spontaneity of Processes
Endothermic Reactions
Endothermic reactions absorb heat from their surroundings, resulting in a positive change in enthalpy (ΔH > 0). While these reactions require energy input to proceed, they can still be spontaneous if the increase in entropy (ΔS) is sufficiently large to offset the energy absorbed, leading to a negative ΔG.
Video consigliato:
Percorso guidato
02:30Endothermic & Exothermic Reactions
Gibbs Free Energy Equation
The Gibbs free energy equation, ΔG = ΔH - TΔS, relates the change in free energy to enthalpy and entropy changes at a given temperature (T). For a reaction to be spontaneous, the term TΔS must be greater than ΔH, allowing for a negative ΔG even when ΔH is positive, thus enabling endothermic reactions to occur spontaneously.
Video consigliato:
Percorso guidato
01:51Gibbs Free Energy of Reactions
Pratica correlata