Ch. 17: Thermochemistry 17... · 17.4—Calculating Heats of Reaction. 17.1The Flow of Energy - Heat & Work The temperature of lava from a volcano ranges from 550°C to 1400°C. As

Ch 17 Thermochemistry

171ndash The Flow of Energy (Heat and Work)

exothermicendothermic

caloriejoule

heat capacityspecific heat

172ndash Measuring and Expressing Enthalpy Changes

calorimetry

enthalpy

thermochemical equation

173ndash Heat in Changes of State

heat of fusionsolidification

heat of vaporizationcondensation

Honorrsquos only

174mdash Calculating Heats of Reaction

171 The Flow of Energy - Heat amp Work

The temperature of lava

from a volcano ranges

from 550degC to 1400degC As

lava flows it loses heat

and begins to cool You

will learn about heat flow

and why some substances

cool down or heat up

more quickly than others

Thermochemistry

Energy Transformations


Heat Flow q

Heat Flow

Specific heat typical unit of measure is Jg˚C

degrees Celsius is used

Specific Heat

q = mcΔT

Water releases a lot of heat as it cools During freezing weather farmers protect citrus crops by spraying them with water

Because it is mostly

water the filling of a hot

apple pie is much more

likely to burn your

tongue than the crust

172 Measuring amp Expressing Enthalpy Changes

Calorimetry

qsys = -qsurr

Enthalpy

Calorimeter

172 Sample Problem

172 Thermochemical Equations


Exothermic Reaction


Endothermic Reaction

172 Sample Problem

Thermochemical Equations

Try It

17 3 Heat in Changes of State

Heats of Fusion and Solidification


Heats of Vaporization and

Condensation

Heats of Vaporization amp

Condensation

∆Hvap = ndash∆Hcond

Heats of Vaporization and Condensation

Phase Change Equations and Constants

Heat Constants for Watercs = 2060 JgdegCHfusi = 334 Jgcl = 4180 JgdegCHvap = 2260 JgCg = 187 JgdegC

ΔHfus is given in textbook

Try It

Calculate the amount of heat absorbed to liquefy 150 g of methanol (CH3OH) at its melting point The molar heat of fusion for methanol is 316 kJmol

a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ

Convert 15 g to moles

molg

molg468750

32

15

Use Qfusion = fusionHm

(046875)(316)

Honorrsquos only

174 Calculating Heats of Reaction

Formation of gems like diamonds and emeralds

Hessrsquos Law

Hessrsquos Law in Action

Hessrsquos Law conti

Standard Heats of Formation ΔHf˚

Standard Heats of Reaction

ΔH˚ = ΔHf˚(products ) - ΔHf˚ (reactants)

171 The Flow of Energy - Heat amp Work

The temperature of lava

from a volcano ranges

from 550degC to 1400degC As

lava flows it loses heat

and begins to cool You

will learn about heat flow

and why some substances

cool down or heat up

more quickly than others

Thermochemistry



Heat Flow q

Heat Flow



Specific Heat

q = mcΔT





likely to burn your



Calorimetry

qsys = -qsurr

Enthalpy

Calorimeter

172 Sample Problem



Exothermic Reaction



172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law






Thermochemistry



Heat Flow q

Heat Flow



Specific Heat

q = mcΔT





likely to burn your



Calorimetry

qsys = -qsurr

Enthalpy

Calorimeter

172 Sample Problem



Exothermic Reaction



172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law








Heat Flow q

Heat Flow



Specific Heat

q = mcΔT





likely to burn your



Calorimetry

qsys = -qsurr

Enthalpy

Calorimeter

172 Sample Problem



Exothermic Reaction



172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law







Heat Flow q

Heat Flow



Specific Heat

q = mcΔT





likely to burn your



Calorimetry

qsys = -qsurr

Enthalpy

Calorimeter

172 Sample Problem



Exothermic Reaction



172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law






Heat Flow q

Heat Flow



Specific Heat

q = mcΔT





likely to burn your



Calorimetry

qsys = -qsurr

Enthalpy

Calorimeter

172 Sample Problem



Exothermic Reaction



172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law






Heat Flow



Specific Heat

q = mcΔT





likely to burn your



Calorimetry

qsys = -qsurr

Enthalpy

Calorimeter

172 Sample Problem



Exothermic Reaction



172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law








Specific Heat

q = mcΔT





likely to burn your



Calorimetry

qsys = -qsurr

Enthalpy

Calorimeter

172 Sample Problem



Exothermic Reaction



172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law










likely to burn your



Calorimetry

qsys = -qsurr

Enthalpy

Calorimeter

172 Sample Problem



Exothermic Reaction



172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law







Calorimetry

qsys = -qsurr

Enthalpy

Calorimeter

172 Sample Problem



Exothermic Reaction



172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law






Calorimetry

qsys = -qsurr

Enthalpy

Calorimeter

172 Sample Problem



Exothermic Reaction



172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law






Enthalpy

Calorimeter

172 Sample Problem



Exothermic Reaction



172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law






Calorimeter

172 Sample Problem



Exothermic Reaction



172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law






172 Sample Problem



Exothermic Reaction



172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law








Exothermic Reaction



172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law







Exothermic Reaction



172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law








172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law






172 Sample Problem


Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law







Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law






Try It





Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law










Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law









Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law








Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law







Condensation


Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law







Condensation






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law










Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law









Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law







Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law






Try It


a) 148 kJ

b) 474 kJ

c) 152 103 kJ

d) 475 kJ


molg

molg468750

32

15


(046875)(316)

Honorrsquos only



Hessrsquos Law






Honorrsquos only



Hessrsquos Law






Hessrsquos Law




















Documents

Ch. 17: Thermochemistry 17... · 17.4—Calculating Heats of Reaction. 17.1The Flow of Energy - Heat & Work The temperature of lava from a volcano ranges from 550°C to 1400°C. As