Calculate how many moles of NO2 form when each quantity of r
Calculate how many moles of NO2 form when each quantity of reactant completely reacts.
 2N2O5(g)4NO2(g)+O2(g)
a. 3.0 mol N2O5
b. 7.2 mol N2O5
c. 17.0 g N2O5
d. 3.39 kg N2O5
Solution
from reaction,
 moles of NO2 formed = (4/2)*number of moles of N2O5 reacting
 = 2*number of moles of N2O5 reacting
a)
 moles of NO2 formed = 2*number of moles of N2O5 reacting
 = 2*3.0 mol
 = 6.0 mol
 Answer: 6.0 mol
b)
 moles of NO2 formed = 2*number of moles of N2O5 reacting
 = 2*7.2 mol
 = 14.4 mol
 Answer: 14.4 mol
c)
 
 Molar mass of N2O5,
 MM = 2*MM(N) + 5*MM(O)
 = 2*14.01 + 5*16.0
 = 108.02 g/mol
 
 
 mass(N2O5)= 17.0 g
 
 use:
 number of mol of N2O5,
 n = mass of N2O5/molar mass of N2O5
 =(17.0 g)/(108.02 g/mol)
 = 0.157 mol
moles of NO2 formed = 2*number of moles of N2O5 reacting
 = 2* 0.157 mol
 = 0.314 mol
 Answer: 0.314 mol
d)
 
 mass(N2O5)= 3.39 Kg
 = 3390 g
 
 use:
 number of mol of N2O5,
 n = mass of N2O5/molar mass of N2O5
 =(3390.0 g)/(108.02 g/mol)
 = 31.4 mol
 moles of NO2 formed = 2*number of moles of N2O5 reacting
 = 2* 31.4 mol
 = 62.8 mol
 Answer: 62.8 mol


