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

Solution: One mole of H2O(g) at 1.00 atm and 100.°C occupies a volume of 30.6 L. When 1 mole of H2O(g) is condensed to 1 mole of H2O(l) at 1.00 atm and 100.°C, 40.66 kJ of heat is released. If the density of H2

Solution: One mole of H2O(g) at 1.00 atm and 100.°C occupies a volume of 30.6 L. When 1 mole of H2O(g) is condensed to 1 mole of H2O(l) at 1.00 atm and 100.°C, 40.66 kJ of heat is released. If the density of H2

Problem

One mole of H2O(g) at 1.00 atm and 100.°C occupies a volume of 30.6 L. When 1 mole of H2O(g) is condensed to 1 mole of H2O(l) at 1.00 atm and 100.°C, 40.66 kJ of heat is released. If the density of H2O(l) at this temperature and pressure is 0.996 g/cm3, calculate ΔE for the condensation of 1 mole of water at 1.00 atm and 100.°C.

Solution

The change in internal energy of a system ΔE is related to heat and work by the equation:

Where q is heat and w is work.


The sign of q changes depending on the type of reaction:

(+) q when a system absorbs heat or energy (endothermic)

(-) q when the system releases energy(exothermic)


In the given problem, 40.66 kJ of heat is released when the 1 mole of H2O(g) is condensed to 1 mole of H2O(l). Therefore, the value of q = -40.66 kJ.


Let us now determine the value for work.


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