30 January 2012. Objective : You will be able to: review and discuss answers to the midterm exam. Agenda. Objective and Agenda Opportunities Midterm exam answers and discussion Homework : Read p. 174-194 Tomorrow: Gases! . Field Trip Opportunity.
Homework: Read p. 174-194
1.01x105Pascals = 101 kPa = 1 atm= 760 mm Hg = 760 torr
1 atm and 0oC.
Boyle’s Law: P1V1=P2V2
ideal gas: a hypothetical gas whose pressure, volume and temperature behavior is completely described by the ideal gas equation
Homework: p. 217 #35, 37, 39, 41, 51, 53 – Mon., read lab and do pre-lab questions in lab notebook - tomorrow
Gasoline is a mixture of many hydrocarbon compounds but its chemical formula can be approximated as C8H18. How many liters of carbon dioxide gas are formed at 25.0oC and 712 torr when 1.00 gallon of liquid gasoline is burned in excess air? Liquid gasoline has a density of 0.690 g/mL. One gallon = 3.80 L
Homework: p. 218 #63, 65, 67, 69, 71, 93, 95
What is the density of sulfur dioxide gas at 35oC and 1270 torr?
A series of measurements are made to determine the molar mass of an unknown gas. First, a large flask is evacuated and found to weight 134.567 g. It is then filled with the gas to a pressure of 735 torr at 31oC and reweighed. Its mass is now 137.456 g. Finally, the flask is filled with water at 31oC and found to weigh 1067.9 g. Calculate the molar mass of the unknown gas.
(The density of the water at this temperature is 0.997 g/mL)
Ptotal = P1 + P2 + P3 + …
mole fraction: the ratio of moles of one gas to the total moles of gas in a mixture
X1 = n1/nt
Each gas in a mixture behaves independently of all the other gases in the mixture and obeys the ideal gas law.
A mixture of 9.00 g oxygen, 18.0 g argon and 25.0 g of carbon dioxide exerts a pressure of 2.54 atm. What is the partial pressure of argon in the mixture?
Homework: Book work assigned yesterday
Lab notebook: due Monday
a. What is the mass of the solid NH4Cl formed when 73.0 g of NH3 gas are mixed with an equal mass of HCl gas?
b. What is the volume of the gas remaining, measured at 14.0oC and 752 mmHg? Which gas is it (NH3 or HCl)?
Homework: Gases problem set: Mon.
H2O(g), CH4(g), Ne
Justify your answer