Ch 1 Flashcards
Total volume of a substance divided by total mass of substance.
Specific Volume
Total mass of substance divided by total volume occupied by that substance.
The … of a substance is the reciprocal of its specific volume.
Density
Measure of the relative density of substance compared to density of water at standard temperature.
Specific Gravity
Amount of moisture in the air.
Absolute Humidity - mass of water vapor divided by unit volume of air.
Relative Humidity - amount of water vapor present in the air divided by maximum amount air could contain at that temperature.
Humidity
Independent of the amount of mass.
Ex. Temp, pressure, density
Intensive Property
The value varies directly with the mass.
Ex. Mass and total volume
Extensive Property
Measure of molecular activity in a substance. The greater the movement of molecules, the higher the ….
Temperature
Measure of force exerted per unit area on boundaries of a substance. As molecules hit walls, they exert forces pushing wall outward.
Pressure
Freezing pt: 32 f
Boiling pt: 212 f
F to C
C= 5/9 F-32
Fahrenheit
Freezing point: 0c
Boiling point: 100c
F= 9/5c +32
Celsius
Absolute 0: -273c
Freezing point: 273 k
Boiling point: 373 k
Kelvin= c + 273
Kelvin
Absolute 0: 0r
Freezing point: 492r
Boiling point: 672r
Rankine= f + 460
Rankine
Relationship between absolute pressure, gauge pressure and vacuum
Absolute pressure is measured relative to a perfect vacuum. psia
Gauge pressure is measured relative to atmospheric pressure. psig
- 7 psia = 408 in of water = 1atm
- 7 psia = 29.9 in of mercury = 1 atm
1 in of mercury = 25.4 mm of mercury
1 mm of mercury = 103 microns of mercury
Converting between Units
