Changes in Stateo Vapor Pressure
▫ observation▫ definition▫ temperature dependence
o Changes in State▫ enthalpies▫ heating curves
o Phase Diagrams▫ special points ▫ examples
CTR
HP vapvap
1)ln(
Vapor Pressureo Dfns.
▫ pres. of vapor present above a (l) or (s)
▫ Hvap energy to convert 1 mole liquid to gas at 1 atm
o Eq. Vapor Pressure▫ rate of evaporation =
rate of condensationo Measuring Pvapor
▫ Hg columnPvapor = Patm – PHg column
Temperature Dependence
Temperature Dependence
CTR
HP vapvap
1)ln(
R = 8.3145 J/mol•KT = temperature (K)C = const. related to S
Changes in State: Heating Curve
Changes in State: Heating Curve
condensation
evaporation
Changes in State: Heating Curve
condensation
evaporation
melting
freezing
Changes in State: Heating Curve
condensation
evaporation
melting
freezing enthalpy of vaporization
Changes in State: Heating Curve
condensation
evaporation
melting
freezing enthalpy of vaporization
enthalpy of fusion
Phase Diagramso Represents the
phases of a material at various T and P in a closed system
o Experiments▫ 1: T at P = 1 atm
http://cwx.prenhall.com/petrucci/medialib/media_portfolio/text_images/FG13_18.JPG
Iodine
(546 C)
(0.118 atm)
1
Phase Diagramso Represents the
phases of a material at various T and P in a closed system
o Experiments▫ 1: T at P = 1 atm▫ 2: T at P = 0.01 atm
http://cwx.prenhall.com/petrucci/medialib/media_portfolio/text_images/FG13_18.JPG
Iodine
(546 C)
(0.118 atm)
2
1
Phase Diagramso Represents the
phases of a material at various T and P in a closed system
o Experiments▫ 1: T at P = 1 atm▫ 2: T at P = 0.01 atm▫ 3: T at P = 0.118 atm
http://cwx.prenhall.com/petrucci/medialib/media_portfolio/text_images/FG13_18.JPG
Iodine
(546 C)
(0.118 atm)32
1
Phase Diagramso Represents the
phases of a material at various T and P in a closed system
o Experiments▫ 1: T at P = 1 atm▫ 2: T at P = 0.01 atm▫ 3: T at P = 0.118 atm▫ 4: T at P = 1 atm
http://cwx.prenhall.com/petrucci/medialib/media_portfolio/text_images/FG13_18.JPG
Iodine
(546 C)
(0.118 atm)32
1
4
Phase Diagramso Represents the
phases of a material at various T and P in a closed system
o Experiments▫ 1: T at P = 1 atm▫ 2: T at P = 0.01 atm▫ 3: T at P = 0.118 atm▫ 4: T at P = 1 atm▫ 5: P at T = 100. C
http://cwx.prenhall.com/petrucci/medialib/media_portfolio/text_images/FG13_18.JPG
Iodine
(546 C)
(0.118 atm)32
1
4
5
Phase Diagramso Represents the
phases of a material at various T and P in a closed system
o Experiments▫ 1: T at P = 1 atm▫ 2: T at P = 0.01 atm▫ 3: T at P = 0.118 atm▫ 4: T at P = 1 atm▫ 5: P at T = 100. C▫ 6: P at T = 150. C
http://cwx.prenhall.com/petrucci/medialib/media_portfolio/text_images/FG13_18.JPG
Iodine
(546 C)
(0.118 atm)32
1
4
5 6
Phase Diagrams: Water
Phase Diagrams: Water
