Announcements

Assignment: Due Wednesday 12/15/99 5:00 pm
Chapter 12 Homework Set and
Questions: 10,14,16,20,24,26,28,30,32,38,44,46,56,60,70,82,92,102.
 
 

Introduction to Gas Laws

Solutions to Lecture Problems

Gas Law Spreadsheet (123; Excel)

   1.Measurements
        a.Pressure (what it is and units)
           Pa
                       (N/m2)
                                  101325 Pa = 1 atm
           bar
                       (105 Pa)
                                  1.01325 bar = 1 atm
           torr and mmHg
                       (133.322 Pa)
                                  760 torr = 1 atm
           atmosphere
                       (101325 Pa)
           PSI
                       (6894.76 Pa)
                                  14.7 PSI = 1 atm
 

        b.Temperature (Use Kelvin Scale, 273.15)

        c.Volume conversions
           Unit
                   Liter
                              m3
           m3
                   10-3
                              1
           cm3 (ml)
                   103
                              106
           liter (dm3)
                   1
                              103
           ft3
                   0.02831
                              28.31
           in3
                   1.639 x 10-5
                              0.01639
 

   2.Introduce concept of an ideal gas
        a.No volume
        b.No interaction
        c.Discuss behavior of ideal gas

   3.Standard Temperature and Pressure (STP)
        a.1 bar (105 Pa), previously 1 atm
        b.0 °C

   4.Boyle's Law (PV = CB)
        a.Derive relationship from ideal gas "concept with picture on board
        b.Animation from CD-ROM (f:, h:, internet)
        c.Graph relationship
        d.Write equation for graph
        e.Work a problem. Given an initial volume of 350 in3 and a compression ratio of 10:1, what is the final volume?

   5.P/T = C
        a.Derive relationship from ideal gas "concept with picture on board
        b.Animation from CD-ROM (f:, h: internet)
        c.Graph relationship
        d.Write equation for graph
        e.Work a problem. A pressure cooker starts out at 25 C and 1 atm pressure. What is the pressure at 200 C?

   6.Charles Law (V/T = CC)
        a.Derive relationship from ideal gas "concept with picture on board
        b.Graph relationship
        c.Write equation for graph
        d.Work a problem. 1 m3 of steam is heated from 100 C to 500 C at constant pressure. What is the final volume?

   7.P/n = C
        a.Derive relationship from ideal gas "concept with picture on board
        b.Animation from CD-ROM ( f:, h: internet)
        c.Graph relationship
        d.Write equation for graph
        e.Work a problem.

   8.Combine above equations to get (PV)/T = C
 

   9.Practice Problems.
        a.A stratospheric sampling balloon starts at sea level, 760 torr and 20 C with a volume of 1000 m3. The balloon
          rises to a pressure altitude of 1000 Pa (appx 40 km) where the temperature is -40 C. What is the volume of the
          balloon at this altitude?

        b.Gas data for 1 gram at STP. Calculate the molar volume
             1.H2 11.1 L
             2.He 5.57 L
             3.N2 0.800 L
             4.Cl2 0.316 L