Question

The compound acrylonitrile can be made in the following reaction: 2C3H6(g) + 2NH3(g) + 3O2(g) → 2C3H3N(g) + 6H2O(g) A 250.0 L reaction vessel is charged to the following partial pressures at 500°C: PC3H6 = 10.0 atm PNH3 = 12.0 atm PO2 = 9.0 atm

A) What is the total pressure in the vessel just after the reagent gases are added (assume ideal behavior)?  

B) What are the mole ratios of the reagent gases in the vessel before the reaction begins?

C)What is the total pressure in the chamber after the reaction has gone to completion (i.e. all

of at least one of the reactants is used up)?

D) What is the partial pressure of acrylonitrile in the vessel after the reaction has gone to

completion?

E) What mass of acrylonitrile is produced after the reaction has gone to completion?

Answer 1

a)

total P in vessel...

Pinitial = PC3H6 + PNH3 +PO2

Pinitial = 10+12+9 = 31 atm

b)

mole ratios:

x-C3H3 = PC3H6 /PTotal = 10/31 = 0.322 atm

x-NH3 = PNH3 / Ptotal = 12/31 = 0.38709 atm

x-O2 = PO2 /PTotal = 9/31 = 0.2903 atm

c)=

Total P after reaction goes to completion...

identify limiting reactant

2:2:3

Oxygen is limiting

9 atm of O2 reacts with ->

P-C3H6 = 2/3*10 = 6.667 atm

P-NH3= 2/3*12 = 8 atm

After reaction:

P-O2 = 0

P-C3H6 = 10-6.667 = 3.33 atm

P-NH3 left = 12-8 = 4 atm

then... 9 atm of O2 forms:

P-C3H3N = 2/3*9 = 6 atm

P-H2O= 6/3*9 = 18 atm

Total P = 0 + 3.33 + 4 + 6 +18 = 31.33 atm

d)

P-C3H3N = 2/3*9 = 6 atm

e)

mass of C3H3N ---> from

PV = nRT

n = PV/(RT) = (6)(250)/(0.082*(500+273))

n = 23.6645 mol produced

mass = mol*MW = 23.6645*53.0626

mass = 1255.69 g