Ch.6 - Thermochemistry WorksheetSee 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

Endothermic & Exothermic Reactions

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

Solution: Which produces more heat, Os(s) + 2O2(g) ⟶ OsO4(s) or Os(s) + 2O2(g) ⟶ OsO4(g)? For the phase change OsO4(s) ⟶ OsO4(g),    ΔH = 56.4 kJ

Solution: Which produces more heat, Os(s) + 2O2(g) ⟶ OsO4(s) or Os(s) + 2O2(g) ⟶ OsO4(g)? For the phase change OsO4(s) ⟶ OsO4(g),    ΔH = 56.4 kJ

Problem

Which produces more heat, 

Os(s) + 2O2(g) ⟶ OsO4(s) 

or 

Os(s) + 2O2(g) ⟶ OsO4(g)? 

For the phase change OsO4(s) ⟶ OsO4(g),    ΔH = 56.4 kJ

Solution

Rxn 1: Os(s) + 2O2(g) ⟶ OsO4(s)

Rxn2: Os(s) + 2O2(g) ⟶ OsO4(g)


Comparing the two equations, we can see that the only difference is the state of products. We have a solid for Rxn 1 and gas for Rxn 2.

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