Ch.6 - Thermochemistry See 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

Enthalpy of Formation

See all sections
Sections
Internal Energy
Calorimetry
Hess's Law
Enthalpy of Formation
End of Chapter 6 Problems
Additional Practice
Units of Energy
Endothermic & Exothermic Reactions
Additional Guides
Enthalpy

Solution: Choose the thermochemical equation that illustrates ΔH°f for Li 2SO4. A) 2 Li+(aq) + SO42- (aq) → Li2SO4(aq) B) 2 Li(s) + 1/8 S8(s, rhombic) + 2 O2(g) → Li2SO4(s) C) Li2SO4(aq) → 2 Li +(aq) + SO42-(aq) D) 8 Li2SO4(s) → 16 Li(s) + S 8(s, rhombic) + 16 O2(g) E) 16 Li(s) + S8(s, rhombic) + 16 O2(g) → 8 Li2SO4(s)

Problem

Choose the thermochemical equation that illustrates ΔH°f for Li 2SO4.
A) 2 Li+(aq) + SO42- (aq) → Li2SO4(aq)
B) 2 Li(s) + 1/8 S8(s, rhombic) + 2 O2(g) → Li2SO4(s)
C) Li2SO4(aq) → 2 Li +(aq) + SO42-(aq)
D) 8 Li2SO4(s) → 16 Li(s) + S 8(s, rhombic) + 16 O2(g)
E) 16 Li(s) + S8(s, rhombic) + 16 O2(g) → 8 Li2SO4(s)