Question

The combustion reaction of propane is described by the reaction. c3h8 5o2 → 4h2o 3co2. how many moles of o2 are required to generate 3 moles of co2

Answer 1

C₃H₈   +   5 O₂   →   4 H₂O   +   3 CO₂

mole ratio based on balance equation of  O₂   :   CO₂ i  s    5  :  3
                      C₃H₈   +   5 O₂   →   4 H₂O   +   3 CO₂

∴ if moles of CO₂  =  3 moles
  
then moles of O₂  = (3 moles ÷ 3) × 5
                             
                             =  5 moles   

Answer 2

Answer:

5 moles of $O_{2}$ are required to generate 3 moles of $CO_{2}$

Explanation:

According to given balanced equation, 5 molecules of $O_{2}$ reacts with 1 molecules of $C_{3}H_{8}$ to produce 4 molecules of $H_{2}O$ and 3 molecules of $CO_{2}$.

So, 5 molecules of $O_{2}$ generate 3 molecules of $CO_{2}$ or $(5\times 6.023\times 10^{23})$ molecules of $O_{2}$ generate $(3\times 6.023\times 10^{23})$ molecules of $CO_{2}$

As 1 mol = $6.023\times 10^{23}$ molecules therefore  5 moles of $O_{2}$ are required to generate 3 moles of $CO_{2}$