lecture 8

Question 1

what is a phase diagram

Answer 1

a graph of pressure plotted against temperature.

Question 2

what is a phase boundary

Answer 2

a line on the phase diagram,, it shows the boundary between 2 phases.

it shows where the 2 phases are in equilibrium: G(A) = G(B)

Question 3

what does the clapeyron equation show

Answer 3

tells us change in P for a given change in T ( the slope of the PT equilibrium line)

the slope of the phase boundary

Question 4

special cases of clapeyron equation

Answer 4

• solid/liquid : slope is normally constant and positive (H/TV) except for water!!! (bc it’s volume is less than 0)
• volume of liquid/vapour = V ideal - Clausius Clapeyron equation

Question 5

what do phase diagrams display

Answer 5

the combination of temperature and pressure that different phases exist (where the equilibria between phase are located)

Question 6

what is the gradient of the phase boundary line given by

Answer 6

by the Clapeyron equation

Question 7

for the solid liquid transition,, what is the line normally seen as

Answer 7

a linear line with a positive gradient

except not for water

Question 8

equation for gas - liquid transitions is given by

Answer 8

clausius clapyeron equation

Question 9

clausius clapyeron equation

Answer 9

gas to liquid transition

Question 10

clapyeron equation

Answer 10

solid to liquid transition