Gas Laws and Airbags
The purpose should be several well developed sentences which include references to several of the topics covered in this experiment. This should include both concepts and techniques. The procedure should reference the lab manual and note any changes made in the procedure.
The data section for this experiment should include table like the one below. A balanced chemical equation for the reaction being studied should also be included.
Title
Volume of 6.0 M
CH3COOH
Needed
Success or Failure
Room Temperature: ______________
Room Pressure:_________________
To complete this table you must first calculate the volume of your gas bag in inches, then convert the inches to centimeters and centimeters to mL and finally to liters. Recall that 1 mL = 1cm 3 and 2.54cm = 1 inch. Once you get the volume in mL do not forget to convert it into liters.
Room temperature and room pressure should have been recorded in lab and can be used along with the ideal gas law to determine the moles of gas needed. Rearranging the ideal gas law into the following form will allow you to calculate the moles of CO2.
Where n is the moles of CO2, what you are solving for, P is the pressure of the room (be sure to convert it to atm), V is the volume of your airbag in L, R is the gas constant ( 0.08206 L . atm/ mol . K) and T is room temperature in Kelvin.
Now that you have the moles of CO2 you can determine the moles of NaHCO3 and CH3COOH needed using the balanced chemical equation and the molar ratio. In this case it is easy, they are all 1:1:1, so the moles of CO2, NaHCO3 and CH3COOH are all the same. Using the moles of NaHCO3 and the molecular weight of NaHCO3 calculate the grams of NaHCO3. Finally using the moles of CH3COOH and the concentration of CH3COOH (6.0 M) determine the liters of CH3COOH then convert liters into mL. This can be done using the molarity equation below:
Molarity (M) = moles / L
L = moles / molarity
The column labeled success or failure should be filled in according to the results you got for each airbag test while in lab.
The calculation section should include sample calculations for each column in the data table, be sure to include conversions of units.
The conclusion section should be in paragraph format and discuss the success or failure of each airbag design. This should include the volume of each air bag and the amount of materials used. Along with the components of the airbag you should include a discussion of the reasons for the success or failure of each bag. Also cite any problems or errors that may have occurred in the experiment and any second trials that may have taken place.
Answer the following questions:
1) Is the gas used in this experiment really an "ideal" gas? Explain.
2) The gas production in this experiment is fairly slow, but the production in a car airbag is quite rapid. What is the reason for the difference in the two reactions?