Rank each set of substances in order of increasing standard molar entropy (S°). Explain your reasoning. a. I 2 (g); F 2 (g); Br 2 (g); Cl 2 (g) b. H 2 O(g); H 2 O 2 (g); H 2 S(g) c. C(s, graphite); C(s, diamond); C(s, amorphous)

Hello everyone today. We have the following problem, arrange the following sulfur electrodes in decreasing order of standard molecular entropy. And justify your answer. So we have these three electrodes of sulfur and we are to rank them based on entropy. So recall that entropy is just the degree of chaos or disorder entropy. It's just the measure of chaos or disorder in a system And it involves three main aspects. So first is the phase. So first is the phase and they're ranked as gas having a high entropy than liquids as having a higher entropy than solids. They are also ranked based on complexity. Which is to say that the more elements that you have this is going to equal a higher entropy and lastly their masses, the greater the mass, the greater the entropy. It's not that we have the different aspects that can affect entropy. We can rank them. So if we were to start with our phase, they are all solids. So now we have to move on to their complexity. So their complexities are as follows. So we have our cyclo S. Six which has six suffers our cyclone As seven which has seven suffers. And lastly our cyclo S eight which has eight sulfur in it. And so we said that based on the number of elements. As in if we increase the number of elements we increase the entropy. So they can be ranked by the following or have our sulfur cyclone S. Eight, our sulfur solid Cyclo S. seven. And then lastly our sulfur solid cyclo S six and so with that we have our rankings based on entropy and decreasing order overall. I do hope this helped, and until next time.

Ch.19 - Free Energy & Thermodynamics

All textbooks

Tro 6th Edition

Ch.19 - Free Energy & Thermodynamics

Problem 56

Chapter 19, Problem 56

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)

Verified step by step guidance

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).

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Video duration:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

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.

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.

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.