Question

Fresh snow has just fallen in the Sierra Nevada Mountains so you decide to drive up to Lake Tahoe to and spend a few days there. T he sun is shining and the temperature is a crisp 2 0.0°F. Lake Tahoe is 6230 feet above sea level. At that elevation, the atmospheric pressure is 11. 5 psi. As you drive along, you hit a patch of ice, careen off the road, and hit a snow embankment. The air bag deploys and you walk away with a few minor scrapes

What is the temperature in Kelvin?

What is the pressure in atmospheres?

If the airbag originally contained 141g of sodium azide, how many moles of nitrogen gas are produced from reaction 1?

How many moles of sodium are produced?

What volume of nitrogen is released into the airbag from the first reaction?(Assume the pressure and temperature is the same as you calculated above.)

How many moles of nitrogen are produced in reaction 2?

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Answer 1

(a) The formulla the ^oF to K conversion is

(T^oF - 32) X 5/9 + 273.15 = T K

T^oF = temperature in K scale

(2^oF - 32) X 5/9 + 273.15 = 256.48T K

(b) 14.7 psi = 1atm

1 psi = 1/14.7 atm

11.5psi = (1/14.7) X 11.5 = 0.78 atm

(c) 2NaN3 -----> 2Na + 3N2

Moles of NaN3 in air bag = mass / molar mass = 141g / 65.0 =2.13 moles

2 moles of NaN₃ produce 3 moles of N₂ gas

1 mole of NaN3 will produce 3/2 = 1.5 moles of N₂

moles of N2 produced = 1.5 X 2.13 = 3.2 mol

(d) Volume of N2

PV = nRT

V = nRT / P = 3.2 X 8.314 X 256.48 / 0.78 = 8734.5L