Gaseous butane (CH3(CH2)2 CH3) reacts with gaseous oxygen gas (O2) to produce gaseous carbon dioxide (CO2) and gaseous water (H2O).

Question

If 18.5g of water is produced from the reaction of 34.3g of butane and 87.1g of oxygen gas, calculate the percent yield of water. Round your answer to 3 significant figures.

= _____ %

Answer 1

Write and balance combustion equation C₄H₁₀ + (13/2) O₂ ⇒ 4CO₂ + 5H₂O

You have to find the limiting reactant as well. Probably the easiest way is to do the stoichiometry and calculate the grams of water produced taking each of the reactants and assuming the other is in excess. Whichever one gives you the least amount of water is the LR and you have the theoretical yield. The percent yield is just the th. yield/ actual yield given x 100%f

I'll do the stoichiometric calculation for oxygen as limiting: 87.1 g O₂ (1 mole/32.00 g O₂)(5 Waters/6.5 O₂)(18.016 g W/mole) = g water

You have to do the one for butane limiting.