Airbags contain a mixture of sodium azide, potassium nitrate, and silicon dioxide. A sensor detects a head on collision that cause the sodium azide to be ignited and to decompose forming sodium and nitrogen gas. This gas fills a nylon or polyamide bag such that the front face of the bag travels at a velocity of 150 to 250 miles per hour. This process, from the initial impact of the crash to full inflation of the airbag, takes only about 40 milliseconds. Sodium is very dangerous so the sodium reacts with potassium nitrate present to produce potassium oxide (K2O), sodium oxide (Na2O), and additional N2 gas. The N2 generated in this second reaction also fills the airbag. The metal oxides react with silicon dioxide (SiO2) in a final reaction to produce silicate(glass), which is harmless and stable.
a. Write a balanced chemical equation for the first reaction in the airbag gas generator (the decomposition of NaN3).
b. Write a balanced equation for the net gas-generating reactions (the combination of the first and second reactions).
c. If a car has an airbag that has a volume of 60.0L and the bag requires a pressure of 2.37 atm at 25.00C, calculate the grams of sodium azide needed to inflate the bag.
2. Write a Lewis dot for azide ion showing all its possible resonance structures. Draw the structures illustrating the molecular geometry. Give the name of the molecular geometry around the central atom. Give the hybridization around the central atom.
This looks like it's down your alley.
https://answers.yahoo.com/question/index?qid=20100302133652AAnVmL6
We can't draw structures on this forum. If I can find a lewis dot sturcture the nitride ion I will post as another link.
http://chem-net.blogspot.com/2011/11/lewis-electron-dot-structures-simple_16.html
a. The balanced chemical equation for the decomposition of sodium azide (NaN3) is:
2 NaN3 → 2 Na + 3 N2
b. The balanced equation for the net gas-generating reactions (combination of the first and second reactions) can be obtained by adding the equations together:
2 NaN3 + 2 KNO3 → K2O + Na2O + 3 N2
c. To calculate the grams of sodium azide needed to inflate the airbag, we need to use the ideal gas law equation:
PV = nRT
Where:
P = Pressure (in atm)
V = Volume (in L)
n = moles of gas
R = Ideal gas constant (0.0821 atm·L/mol·K)
T = Temperature (in Kelvin)
We can rearrange the equation to solve for the number of moles:
n = PV / RT
Substituting the given values:
P = 2.37 atm
V = 60.0 L
R = 0.0821 atm·L/mol·K
T = (25.00 + 273.15) K (convert Celsius to Kelvin)
n = (2.37 atm * 60.0 L) / (0.0821 atm·L/mol·K * 298.15 K)
n ≈ 5.47 mol
Since the balanced equation tells us that 2 moles of NaN3 produce 3 moles of N2, we need to convert the moles of N2 to moles of NaN3:
(5.47 mol N2) * (2 mol NaN3 / 3 mol N2) ≈ 3.65 mol NaN3
Finally, to calculate the grams of sodium azide needed, we can use the molar mass of sodium azide (65.01 g/mol):
mass = moles * molar mass
mass = 3.65 mol * 65.01 g/mol ≈ 237.33 g
Therefore, approximately 237.33 grams of sodium azide are needed to inflate the airbag.
2. The Lewis dot structure for azide ion (N3-) is as follows:
N ≡ N ← N-
There are three possible resonance structures for the azide ion. In each structure, nitrogen (N) has a lone pair of electrons and a triple bond with one of the other nitrogen atoms.
The molecular geometry around the central nitrogen atom in azide ion is linear. The hybridization around the central nitrogen atom is sp.
a. To write a balanced chemical equation for the first reaction in the airbag gas generator, you need to know the formula for sodium azide (NaN3). Sodium azide decomposes into sodium (Na) and nitrogen gas (N2) when ignited. The balanced chemical equation for this reaction is:
2 NaN3 -> 2 Na + 3 N2
b. To write a balanced equation for the net gas-generating reactions, you need to combine the first reaction (decomposition of sodium azide) with the second reaction (reaction of sodium with potassium nitrate). From the given information, we know that sodium reacts with potassium nitrate to produce potassium oxide (K2O), sodium oxide (Na2O), and additional nitrogen gas (N2). The balanced chemical equation for this net reaction is:
10 NaN3 + 2 KNO3 -> 5 Na2O + K2O + 6 N2
c. To calculate the grams of sodium azide needed to inflate the airbag, we need to use the ideal gas law equation: PV = nRT. In this case, the pressure (P) is given as 2.37 atm, the volume (V) is given as 60.0 L, the temperature (T) is given as 25.00°C (which needs to be converted to Kelvin by adding 273.15), and the gas constant (R) is 0.0821 L•atm/mol•K.
First, convert the temperature from Celsius to Kelvin:
25.00 + 273.15 = 298.15 K
The ideal gas law equation can be rearranged to solve for the number of moles (n) of sodium azide:
n = PV / RT
Substituting the given values:
n = (2.37 atm) * (60.0 L) / (0.0821 L•atm/mol•K) * (298.15 K)
Solving for n:
n = 59.682 mol
Since the molar mass of sodium azide (NaN3) is 65.01 g/mol, we can calculate the grams (m) of sodium azide needed:
m = n * Molar mass
m = (59.682 mol) * (65.01 g/mol)
m ≈ 3882.77 g
Therefore, approximately 3882.77 grams of sodium azide are needed to inflate the airbag.
2. The Lewis dot structure for the azide ion (N3-) includes all the possible resonance structures, which depict the placement of electrons around the atoms involved. The Lewis dot structure for the azide ion is shown as follows:
N≡N: - N:
In this structure, the central nitrogen (N) atom is bonded to two terminal nitrogen atoms (N), each with a triple bond. The central nitrogen atom also has one lone pair of electrons. The molecular geometry around the central nitrogen atom is linear, and the hybridization around the central nitrogen atom is sp hybridization.