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: In the standard enthalpy of formation, ΔH°f , for nitrogen(IV) oxide, NO2, is the enthalpy change for which reaction?  (A) N(g) + 2O(g) → NO2(g) (B) 1/2N2(g) + O2(g) → NO2(g) (C) 1/2N2O4(g) → NO2(g) (D) NO(g) + 1/2O2(g) → NO2(g)

Problem

In the standard enthalpy of formation, ΔH°, for nitrogen(IV) oxide, NO2, is the enthalpy change for which reaction? 

(A) N(g) + 2O(g) → NO2(g)

(B) 1/2N2(g) + O2(g) → NO2(g)

(C) 1/2N2O4(g) → NO2(g)

(D) NO(g) + 1/2O2(g) → NO2(g)