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

See all sections
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: Given w = 0, an endothermic reaction has which of the following:a. +ΔH and +ΔEb. -ΔH and -ΔEc. +ΔH and -ΔEd. -ΔH and +ΔE

Solution: Given w = 0, an endothermic reaction has which of the following:a. +ΔH and +ΔEb. -ΔH and -ΔEc. +ΔH and -ΔEd. -ΔH and +ΔE

Problem

Given w = 0, an endothermic reaction has which of the following:

a. +ΔH and +ΔE

b. -ΔH and -ΔE

c. +ΔH and -ΔE

d. -ΔH and +ΔE

Solution

We’re being asked to determine the signs of ΔH and ΔE given w = 0 and that the reaction is endothermic.


Work is given by the equation:

w=-PV

When work is equal to 0, there’s no change in volume or the volume is constant.


For ΔH, recall endothermic and exothermic reactions:

Exothermic reactions

lose energy, releases heat, the temperature of the surroundings increases
▪ involves bond formation (for phase change: gas → liquid → solid)
ΔH is negative

Endothermic reactions

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