Ch. 17 - Chemical ThermodynamicsWorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Solution: For the dissociation reaction of the acid HF HF ⇌ H+ + F - ΔS is observed to be negative. The BEST explanation for this is: A. This is the expected result since each HF molecule produces two ions when it dissociates. B. Hydration of the ions produces the negative value of ΔS. C. The reaction is expected to be exothermic and thus ΔS should be negative. D. The reaction is expected to be endothermic and thus ΔS should be negative. E. None of these can explain the negative value of ΔS.

Problem

For the dissociation reaction of the acid HF

HF ⇌ H+ + F -

ΔS is observed to be negative. The BEST explanation for this is:

A. This is the expected result since each HF molecule produces two ions when it dissociates.

B. Hydration of the ions produces the negative value of ΔS.

C. The reaction is expected to be exothermic and thus ΔS should be negative.

D. The reaction is expected to be endothermic and thus ΔS should be negative.

E. None of these can explain the negative value of ΔS.