Data Table 3: 80-L Driver-Side Air Bag Activity Calculations Moles of CO 2 requi
ID: 549172 • Letter: D
Question
Data Table 3: 80-L Driver-Side Air Bag
Activity
Calculations
Moles of CO2 required to inflate 80-L driver-side air bag at room temperature and pressure
3.25moles
Balanced equation for the reaction of NaHCO3 and CH3COOH
NaHCO3+CHCOOH=CH3COONa+H2O+CO2
Grams of NaHCO3 needed for the reaction
273 g
mL of CH3COOH (0.833 M) needed for the reaction
3.9 L, 3900mL
Data Table 4: 160-L Front Passenger-Side Air Bag
Activity
Calculations
Moles of CO2 required to inflate 160-L front passenger-side air bag at room temperature and pressure
7.14 moles
Balanced equation for the reaction of NaHCO3 and CH3COOH
NaHCO3+CHCOOH=CH3COONa+H2O+CO2
Grams of NaHCO3 needed for the reaction
599.76, 600 grams
mL of CH3COOH (0.833 M) needed for the reaction
8.57L, 8470mL
Based upon the observed performance of the air bag models and the amounts of sodium bicarbonate and acetic acid (vinegar) needed for an automotive air bag of 80 or 160 L, are these reactants a good substitute for sodium azide? One additional note regarding sodium azide: the rate of inflation after a triggering impact is 40 milliseconds (0.04 s).
Activity
Calculations
Moles of CO2 required to inflate 80-L driver-side air bag at room temperature and pressure
3.25moles
Balanced equation for the reaction of NaHCO3 and CH3COOH
NaHCO3+CHCOOH=CH3COONa+H2O+CO2
Grams of NaHCO3 needed for the reaction
273 g
mL of CH3COOH (0.833 M) needed for the reaction
3.9 L, 3900mL
Explanation / Answer
Recall that
2NaN3(s) = 2Na(s)+ 3N2(g)
mol of N2 required to fill up 80 L --> 80/22.4 = 3.57 mol of N2
mol of NaN3 = 2/3*3.57 = 2.38 mol of NaN3
mass = mol*MW = 2.38*65.00987 = 154.72 g
Density of NaN3# --> 1.85 g/mL
V = masS/D = 154.72/1.85
V = 83.632 mL required
which is much less than 3.9 L and 8.57 L
that is...
this is still much more effective
avoid new "alternatives" remain with NaN3
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.