Ch. 17 - Chemical ThermodynamicsWorksheetSee all chapters
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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: For each phase change, determine the sign of ΔH and ΔS.Sublimation ,Freezing, Condensation, Deposition, Boiling , Melting a)   +ΔH,+ΔSb) -ΔH, -ΔSc) +ΔH, -ΔSd) -ΔH, +ΔSPut the phase change to the corre

Solution: For each phase change, determine the sign of ΔH and ΔS.Sublimation ,Freezing, Condensation, Deposition, Boiling , Melting a)   +ΔH,+ΔSb) -ΔH, -ΔSc) +ΔH, -ΔSd) -ΔH, +ΔSPut the phase change to the corre

Problem

For each phase change, determine the sign of ΔH and ΔS.

Sublimation ,Freezing, Condensation, Deposition, Boiling , Melting

 

a)   +ΔH,+ΔS

b) -ΔH, -ΔS

c) +ΔH, -ΔS

d) -ΔH, +ΔS

Put the phase change to the correct sign of ΔH and ΔS

Solution

During phase changes the signs for ΔH and ΔS are the same.

Breaking bonds requires absorbing energy (+ΔH) and increasing disorder (+ΔS)

Forming bonds requires releasing energy (- ΔH) and decreasing disorder (- ΔS)

Sublimation: phase transition from solid to gas state. Need energy to melt solid into gaseous form which means this is an endothermic process, so ΔH will be positive. Disorder increases as we transition from solid --->liquid---->gas, ΔS will be positive as well...

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