1. Processes and Process Variables
Chapter 3

2. Mass and Volume Density Specific Volume Specific Gravity
mass/unit volume
g/cm3
Specific Volume
volume/ unit mass
cm3/g
Specific Gravity
Dimensionless

3. Specific Gravity
Ratio of the density of a substance to a reference substance at a specific condition
SG=r/rref
The reference is often the density of water at 4 C
1.000 g/cm3

4. What Does this mean?
The density of the substance, measured at 20 C, is only 60% of the density of water, measured at 4 C

5. Flow Rate
Mass flow rate
Mass/time
Volumetric flow rate
Volume/time

6. Flow Rate Measurement
Flowmeter
Rotameter
Orifice Meter

7. Moles and Molecular Weight
Atomic Weight
Molecular Weight
gram-mole
lb-mole

8. Mass and Mole Fraction
Mass fraction
Mole fraction

9. Concentration Mass concentration Molar concentration Molarity
Mass/volume
Molar concentration
Moles/unit volume of the mixture
Molarity
Molar concentration in gram moles per liter of solution
ppm and ppb

10. Pressure Measured in psi, pascals, bars Head
Height of a column of water or mercury
1 atm = a head of 33.9 ft of water
1 atm = a head of 760 mm of Hg

11. Atmospheric Pressure Absolute pressure Gauge pressure
Pabsolute = Pgauge + Patmospheric

12. Pressure Measurement Bourdon Gauge Manometer Barometer
We’ve covered all of this in thermodynamics

13. Temperature We’ve been here too
Be sure you can use your calculator to make conversions between English and SI units

14. Next time - Homework Test on Tuesday 3.23 3.3 3.30 3.6 3.31 3.7 3.45
3.50
3.3
3.6
3.7
3.13
3.14
3.16
3.17
Test on Tuesday