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 54
Capitolo 19, Problema 54

Rank each set of substances in order of increasing standard molar entropy (S°). Explain your reasoning. a. I2(g); F2(g); Br2(g); Cl2(g) b. H2O(g); H2O2(g); H2S(g) c. C(s, graphite); C(s, diamond); C(s, amorphous)

Guida verificata passo dopo passo
1
Identify the substances involved: graphite, diamond, and amorphous carbon, all of which are allotropes of carbon.
Recall that standard molar entropy (S°) is a measure of the disorder or randomness of a system. Generally, more ordered structures have lower entropy.
Consider the structure of each allotrope: Graphite has a layered structure with more freedom of movement between layers, diamond has a rigid 3D lattice, and amorphous carbon lacks a long-range order.
Compare the order of the structures: Diamond, with its highly ordered lattice, is expected to have the lowest entropy. Graphite, with its layered structure, is more disordered than diamond. Amorphous carbon, being the least ordered, should have the highest entropy.
Rank the substances in order of increasing standard molar entropy: C(s, diamond) < C(s, graphite) < C(s, amorphous).

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:
2m

Concetti chiave

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

Standard Molar Entropy

Standard molar entropy (S°) is a measure of the randomness or disorder of a substance at standard conditions (1 bar, 25°C). It reflects the number of accessible microstates for a given amount of substance, with higher values indicating greater disorder. Entropy increases with temperature, molecular complexity, and the number of particles in a system.
Video consigliato:
Percorso guidato
03:33
Standard Molar Entropy

Allotropes of Carbon

Carbon exists in several allotropes, including graphite, diamond, and amorphous carbon. Each allotrope has a distinct arrangement of carbon atoms, affecting its physical properties and entropy. Graphite has a layered structure allowing for more disorder, while diamond has a rigid, ordered structure, and amorphous carbon lacks a defined structure, contributing to its higher entropy.
Video consigliato:
Percorso guidato
03:48
3 and 4 Carbon Alkyls

Factors Affecting Entropy

Several factors influence the standard molar entropy of substances, including molecular structure, phase (solid, liquid, gas), and temperature. Generally, gases have higher entropies than liquids, and liquids have higher entropies than solids. Among solids, those with more complex structures or greater molecular motion tend to have higher entropies, which is crucial for ranking the given carbon allotropes.
Video consigliato:
Percorso guidato
01:21
Factors Affecting Entropy
Pratica correlata
Domanda del libro di testo

For each pair of substances, choose the one that you expect to have the higher standard molar entropy (S°) at 25 °C. Explain your choices. a. CO(g); CO2(g) b. CH3OH(l); CH3OH(g) c. Ar(g); CO2(g) d. CH4(g); SiH4(g) e. NO2(g); CH3CH2CH3(g) f. NaBr(s); NaBr(aq)

1639
views
Domanda del libro di testo

Rank each set of substances in order of increasing standard molar entropy (S°). Explain your reasoning. a. NH3(g); Ne(g); SO2(g); CH3CH2OH(g); He(g) c. CH4(g); CF4(g); CCl4(g)

2273
views
2
rank
Domanda del libro di testo

Use data from Appendix IIB to calculate ΔS°rxn for each of the reactions. In each case, try to rationalize the sign of ΔS°rxn . b. C(s) + H2O(g) → CO(g) + H2(g)

2217
views
1
rank
Domanda del libro di testo

Rank each set of substances in order of increasing standard molar entropy (S°). Explain your reasoning. b. H2O(s); H2O(l); H2O(g)

562
views
Domanda del libro di testo

Use data from Appendix IIB to calculate ΔS°rxn for each of the reactions. In each case, try to rationalize the sign of ΔS°rxn. c. CO(g) + H2O(g) → H2(g) + CO2(g)

445
views