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: Calculate the enthalpy of the reaction4B(s) + 3O2(g) → 2B2O3(s)given the following pertinent information:B2O3(s) + 3H2O(g) → 3O2(g) + B2H6(g),      ΔH∘A=+2035 kJ2B(s) + 3H2(g) → B2H6(g),              

Problem

Calculate the enthalpy of the reaction

4B(s) + 3O2(g) → 2B2O3(s)

given the following pertinent information:

B2O3(s) + 3H2O(g) → 3O2(g) + B2H6(g),      ΔHA=+2035 kJ

2B(s) + 3H2(g) → B2H6(g),                            ΔHB=+36 kJ

H2(g) + 1/2 O2(g) → H2O(l),                            Δ  HC=−285 kJ

H2O(l) → H2O(g),                                          ΔHD=+44 kJ

Express your answer with the appropriate units.