Percent yield and round the answer to 3 signficant figures

Question

Liquid hexane CH3CH24CH3

 reacts with gaseous oxygen gas O2

 to produce gaseous carbon dioxide CO2

 and gaseous water H2O

. If 67.2g

 of water is produced from the reaction of 64.63g

 of hexane and 291.8g

 of oxygen gas, calculate the percent yield of water. 

Round your answer to 3

 significant figures. 

_______%

Answer 1

I'm taking the liberty of shortening the hexane formula to the equivalent C₃H₃₀. This makes it easier to type and to balance the reaction: 2 C₃H₃₀ + 15 O₂ --> 6 CO₂ + 30 H₂O.

64.63g C₃H₃₀ * (1 mol C₃H₃₀ / 66.24g C₃H₃₀) * (30 mol H₂O / 2 mol C₃H₃₀) = 14.635 mol H₂O.

291.8g O₂ * (1 mol O₂ / 32.00g O₂) * (30 mol H₂O / 15 mol O₂) = 18.24 mol H₂O.

Hexane is then the limiting reactant. 14.635 mol H₂O * (18.02g H₂O / 1 mol H₂O) = 263.7g H₂O theoretical yield. Percent yield = 100 * actual/theoretical = 100 * 67.2/263.7 = 25.5%