Calculate the number of moles of carbon dioxide formed when 40.0 moles of oxygen is consumed in the burning of propane. note the equation is unbalanced.

c3h8 + o2 > co2 + h2o :

a. 40.0 mol co2

b. 42.0 mol co2

c. 20.0 mol co2

d. 24.0 mol co2

The first step is to balance the equation:

C3H8 + 5O2 ---> 3CO2 + 4H2O

Check the balance

element          left side        right side

C                    3                  3  
H                    8                  4*2 = 8
O                    5*2=10        3*2 + 4 = 10

Then you have the molar ratios:

3 mol C3H8 : 5 mol O2 : 3 mol CO2 : 4 mol H2O

Now you have 40 moles of O2 so you make the proportion:

40.0 mol O2 * [3 mol CO2 / 5 mol O2] = 24.0 mol CO2.

option D. 24.0 mol CO2