Concepts to Rvw Pressure –Stand demo –Sound demo Units of pressure –Pa –mm Hg –torr –atm...
-
Upload
sherilyn-bell -
Category
Documents
-
view
217 -
download
0
Transcript of Concepts to Rvw Pressure –Stand demo –Sound demo Units of pressure –Pa –mm Hg –torr –atm...
Conversions in Pressure
1 atm = 760 mm Hg
1 atm = 760 torr
1 atm = 1.01 x 105 Pa or 101 kPa
1 atm = 14 psi
Hmmmm?Why do you almost close your
mouth and blow when you have a burn on your skin to cool it?
Why do you open your mouth wider when you want to warm your hands?
Run through of laws• Equation to know:
P1V1 = P2V2 T must be in Kelvin
T1 T2
• Dalton’s law of partial pressures (duh) next
• Boyle’s law (last class) next
• Charles’ law next
• Gay-Lussac (what you will design) next
Practice prob pg 367
Givens Eq’n
T = 20 oC
Pressure =
Partial press of H = 742.5 torr
Partial press of water = 17.5 torr
?? = room pressure at time
Pg 367 #5
Givens
T = 23 oC
Room pressure = 785 mmHg
Partial pressure of water = 21.1 mm Hg
??? Partial pressure of nitrogen
back
Boyle’s Law• Why does it get harder squeeze as the
volume decreases?
• How does this fit with breathing?
• back
Charles’ Law
• Dillon’s story—why everyone should know science
• Earlier aviation people used balloons
• Reason for Kelvin scale and absolute zero
• back
Guy-Lussac
• Using the pressure sensors, thermometers and a bottle of club soda determine how you can verify G-L law.
• You will need other materials but the set-up if for YOUR group to determine.
Practice
What volume does 0.68 mol of gas occupy at STP?
What quantity of gas, in moles, is 2.21 L @ STP?
Gas Stoichiometry
Propane is use in gas grills. The complete combustion of propane is given by the following:
C3H8 + 5 O2 3CO2 + 4 H2O
What volume, in liters, of oxygen is needed for the complete combustion of 0.35 L of propane?
Pg 382 Practice
What volume of oxygen gas is needed to react completely with 0.626 L of CO to form carbon dioxide? Assume all volume measurements are made at the same temperature and pressure.