Lecture 6

Question 1

Define phase

Answer 1

phase is a form of matter uniform throughout in the chemical composition and physical state

Question 2

Draw a phase diagram and give the labels for phases and boundaries

Question 3

What do the liquid-gas and solid-gas boundaries determine?

Answer 3

liquid-gas= vapour pressure
solid-gas= sublimation pressure

Question 4

Give the Clapeyron equation

Answer 4

page 35

Question 5

Give the Clapeyron equation for the liquid-vapour phase boundary

Answer 5

page 36

Question 6

How does a phase diagram for water differ to a general diagram?

Answer 6

shows anomalous behaviour with a negative slope
due to hydrogen bonding meaning ice is less dense than liquid water allowing it to float

Question 7

what is the triple point?

Answer 7

the 3 phase boundaries meet; solid, liquid and gas coexist in eqm.
Marks the lowest temp at which the liquid phase can exist

Question 8

What is the critical point?

Answer 8

marks the highest T at which the liquid phase can exist

Question 9

What is the normal bpt of water?

Answer 9

99.97 degree C at pressure of 1 atm

Question 10

What is the standard bpt of water?

Answer 10

99.61 degree C at a standard pressure of 100kPa

Question 11

Give the Gibbs phase rule

Answer 11

F = C- P + 2

F= number of degrees of freedom
C= number of components
P= number of phases