1. Pressure and Phase Relationships
Ch. 13 States of Matter

2. Fahrenheit, Celsius and Kelvin
Fahrenheit based on reference temperatures of brine solution at 0 and in mouth at 96 or wife’s armit
Celsius based on freezing pt and boiling point of water]
F = 1.8C + 32
Kelvin based upon absolute zero and no negative values
K = C + 273

3. Pressure
Pressure: Defined as force per unit area caused by gas molecules colliding with surface
P = F/A
1 Pa = 1 N/m2
Temperature: defined as a measure of the AVERAGE kinetic energy of a substance (this means that some molecules are moving faster than average and some slower than average)

4. Liquid-Vapor Equilibrium
The temperature and pressure at which equal amounts of high energy liquid molecules A are escaping to become vapor and vapor molecules B are being slowed down and trapped at surface to return to liquid

5. Barometer (or manometer) measures pressure
SI unit is the pascal (1 Pa = 1 N/m2) or kilopascal kPa
Meteorologists (weather) like mmHg, the height the atmospheres pressure pushes a liquid column upward (more dense liquids don’t get pushed as high and Hg is very dense)
mmHg are also called Torrs, so 1mmHg = 1Torr

6. Gas molecules in the atmosphere
A standard atmosphere (atm) of pressure is defined as typical air pressure at earth mean sea level

7. Pressure conversions 13.3 psi and 690 Torr
1 atmosphere is a measure of the normal pressure at sea level
1 atm = 101.3kPa = 101,300 Pa = 760 mmHg = 760 Torr = 14.7 psi
This means 760mmHg = 14.7psi and 101.3kPa = 760 Torr as well
A typical atmospheric pressure in Fort Collins CO might be 690 mmHg. Convert this to atmospheres of pressure.
690mmHg x 1 atm = atm
760mmHg
Convert the same pressure above into both psi and Torr
13.3 psi and 690 Torr

8. Phase Diagram of Water