Without doing any calculations, determine the sign of ΔSsys for each chemical reaction. a. Mg(s) + Cl 2 (g) → MgCl 2 (s) b. 2 H 2 S(g) + 3 O 2 (g) → 2 H 2 O(g) + 2 SO 2 (g) c. 2 O 3 (g) → 3 O 2 (g) d. HCl(g) + NH 3 (g) → NH 4 Cl(s)

Hello everyone today. We are being asked to identify the sign of delta S of the system, which is essentially the entropy of the system for the reaction below. Without doing calculations. So we have you which is a solid reacting with three moles of flooring gas to produce Your radium F six, which is also a gas. So in order to do this without calculations, we must have, we must look at the number of moles for the reactant and the products For the reactant. We have three moles And for the products, we have one mole going from greater moles to lesser moles indicates a decrease in the entropy or delta S system. Therefore, we are expecting to have a negative sign for delta S of the system. I hope this helped and until next time.

Ch.18 - Free Energy and Thermodynamics

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Tro 4th Edition

Ch.18 - Free Energy and Thermodynamics

Problem 36

Chapter 18, Problem 36

Without doing any calculations, determine the sign of ΔSsys for each chemical reaction. a. Mg(s) + Cl₂(g) → MgCl₂(s) b. 2 H₂S(g) + 3 O₂(g) → 2 H₂O(g) + 2 SO₂(g) c. 2 O₃(g) → 3 O₂(g) d. HCl(g) + NH₃(g) → NH₄Cl(s)

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Identify the states of matter for each reactant and product in the reactions.

Recall that entropy (ΔS) is a measure of disorder or randomness in a system, with gases having higher entropy than liquids or solids.

For reaction (a), note that a gas and a solid react to form a solid, indicating a decrease in entropy (ΔSsys < 0).

For reaction (b), compare the number of gas molecules on both sides of the equation. The number of gas molecules remains the same, suggesting a small change in entropy (ΔSsys ≈ 0).

For reaction (c), observe that the reaction goes from 2 moles of gas to 3 moles of gas, indicating an increase in entropy (ΔSsys > 0).

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Key Concepts

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

Entropy (ΔS)

Entropy, denoted as ΔS, is a measure of the disorder or randomness in a system. In chemical reactions, changes in entropy can indicate whether the products are more or less disordered than the reactants. A positive ΔS suggests an increase in disorder, while a negative ΔS indicates a decrease in disorder.

Phase Changes and Entropy

The phase of a substance significantly affects its entropy. Gases have higher entropy than liquids, which in turn have higher entropy than solids due to the greater freedom of movement and arrangement of particles in gases. Therefore, reactions that produce gases from solids or liquids typically result in a positive ΔS.

Molecular Complexity and Entropy

The complexity and number of molecules in a reaction can influence entropy. Reactions that produce more molecules or more complex molecules generally lead to an increase in entropy. Conversely, reactions that result in fewer or simpler molecules tend to decrease the system's entropy.

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Factors Affecting Entropy

Related Practice

Textbook Question

Without doing any calculations, determine the sign of ΔS_sys 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)

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Textbook Question

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

Textbook Question

Without doing any calculations, determine the signs of ΔS_sys and ΔS surr for each chemical reaction. In addition, predict under what temperatures (all temperatures, low temperatures, or high temperatures), if any, the reaction is spontaneous. a. C₃H₈(g) + 5 O₂(g) → 3 CO₂(g) + 4 H₂O(g) ΔH°_rxn = -2044 kJ

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Textbook Question

Without doing any calculations, determine the signs of ΔS_sys and ΔS_surr for each chemical reaction. In addition, predict under what temperatures (all temperatures, low temperatures, or high temperatures), if any, the reaction is spontaneous. c. 2 N₂(g) + O₂(g) → 2 N₂O(g) ΔH°_rxn = +163.2 kJ

Without doing any calculations, determine the sign of ΔSsys for each chemical reaction. a. Mg(s) + Cl2(g) → MgCl2(s) b. 2 H2S(g) + 3 O2(g) → 2 H2O(g) + 2 SO2(g) c. 2 O3(g) → 3 O2(g) d. HCl(g) + NH3(g) → NH4Cl(s)

Verified video answer for a similar problem:

Key Concepts

Entropy (ΔS)

Phase Changes and Entropy

Molecular Complexity and Entropy

Without doing any calculations, determine the sign of ΔSsys for each chemical reaction. a. Mg(s) + Cl₂(g) → MgCl₂(s) b. 2 H₂S(g) + 3 O₂(g) → 2 H₂O(g) + 2 SO₂(g) c. 2 O₃(g) → 3 O₂(g) d. HCl(g) + NH₃(g) → NH₄Cl(s)