Chemistry Help.?

Question

Sodium azide, NaN3(s), is used to inflate airbags. On impact, the sodium azide is ignited by an electrical spark producing nitrogen gas and solid sodium. The Nitrogen gas inflates the airbag.

1. Using the information above, write a blanced reaction using the smallest whole number coefficient and physical state of each chemical.

2. In terms of atoms, what type of reaction is described above?

3. What is the total number of moles present in a 130g sample of NaN3(s)

4. Assuming all of the sodium azide reactants, how many grams of solid sodium are produced?

5. An inflated airbag has a volume of 5.00 x 10^4 cm^3 at STP. The density of nitrogen gas at STP is 0.00125 g/cm^3. What is the total number of molecules of nitrogen gas in the airbag.

Thanks!

Answer 1

1. 2 NaN3 = 3 N2 + 2 Na

2. in terms of atoms? not sure what the question means.

3. molar mass of NaN3 = 65 g/mole so (130g)/(65g/mole) = 2 moles

4.molar mass of Na = 23g/mol so 46g

5. (1atm)(50L) = n(.08206 L*atm/mol*K)(273K)
solve for n (number of moles)
2.23 moles

OR

more simply (5e4 mL)*(.00125 g/mL) = 62.5g
62.5 g of N2 * molar mass of N2 (28g/mol) = 2.23 moles

Answer 2

1. 2NaN3 ===> 2Na + 3N2

2. Oxidation-reduction. In particular, a disproportionation.

Atomic weights: Na=23 N=14 NaN3=65
130gNaN3 x 1molNaN3/65gNaN3 = 2molNaN3

3. Never mind the density of nitrogen. 22,400ccN2/molN2 and 6.02x10^23moleculesN2/molN2. Go for it!