How many grams of sodium azide are needed to provide sufficient nitrogen gas to fill a 50.0 × 50.0 × 25.0 cm bag to a pressure of 1.15 atm at 25.0 °C?
1 Answer
Explanation:
We're asked to find the mass, in
To do this, we can use the ideal gas equation to find the moles of nitrogen gas present:

#P = 1.15# #"atm"# (given) 
#V# must be in liters, so we can find the volume first in#"cm"^3# and then convert:
#50.0 xx 50.0 xx 25.0 = 62500# #"cm"^3#
#62500cancel("cm"^3)((1cancel("mL"))/(1cancel("cm"^3)))((1color(white)(l)"L")/(10^3cancel("mL"))) = 62.5# #"L"#

#R# is the universal gas constant, equal to#0.082057("L"·"atm")/("mol"·"K")# 
#T = 25.0# #""^"o""C"# , which must be in Kelvin:
#T = 25.0# #""^"o""C" + 273 = 298# #"K"#
Plugging in known values, and solving for the number of moles,
Now, we can use the coefficients of the chemical equation to find the relative number of moles of sodium azide that must react:
Finally, we can use the molar mass of sodium azide (