JV K. answered • 01/15/20

Chemistry (General/Organic) Professor with 18 Years of Experience

Strategy: We can calculate the mole of O_{2} if we know mole of CO_{2} produced based on the balanced chemical equation. Once you know the moles of O_{2}, we can calculate the volume of O_{2}.

So, first we need to find how many moles of CO_{2} are in 11.2 L of CO_{2}.

We know that **at STP ==> 22.4 L of ANY gas = 1 mol of gas**.

Therefore, 11.2 L of CO_{2} at STP ==> (1 mol CO_{2}/22.4 L CO_{2}) * (11.2 L CO_{2}) = 0.500 mol CO_{2} (3 Sig Fig)

According to the balanced equation, to produce 2 moles of CO_{2}, we need 3 moles of O_{2}

Therefore 0.500 mol of CO_{2} would need ==> (3 mol O_{2}/2 mol CO_{2}) * (0.500 mol CO_{2}) = 0.750 mol O_{2}

Now we can convert mole of O_{2} to Liters of O_{2} using same conversion factor at STP.

Volume of O_{2} = (22.4 L O_{2}/1 mol O_{2}) * (0.750 mol O_{2}) ==> 16.8 L of O_{2}