C3H8 + 5 O2 → 3 CO2 + 4 H2O

Question

a. How many liters of propane(C3H8) will produce 5.67 liters of carbon dioxide? 

b. How many moles of propane are needed to produce 5.67 liters of carbon dioxide?

c. What mass of propane is needed to produce 5.67 liters of carbon dioxide?

Answer 1

C₃H₈ + 5 O₂ ==> 3 CO₂ + 4 H₂O ... balanced equation

Since we aren't given any conditions of temperature and pressure, we'll assume standard conditions (STP) which is

Temperature = 273K

Pressure = 1 atm

Also, at STP 1 mole of an ideal gas = 22.4 liters

Finally, for gases, moles and liters are equivalent so one can use the coefficients of the balanced equation.

a) 5.67 L CO₂ x 1 L C₃H₈ / 3 L CO2 = 1.89 liters of C₃H₈

b) 1.89 L C₃H₈ x 1 mol / 22.4 L = 0.0844 moles C₃H₈

c) 0.0844 moles C₃H₈ x 44 g/mol = 3.71 g C₃H₈