Question

If 13.8 grams of pentane are burned in excess oxygen, how many grams of h2o will be produced?

Answer 1

C5H12 + 8O2 ===> 5CO2 + 6H2O

moles C5H12 = grams/molar mass = 13.8/72 = 0.192
Using the coefficients in the balanced equation convert mols C5H12 to mols H2O produced. That's 0.192 mols C5H12 x (6 mols H2O/1 mol C5H12) = 0.192 x 6 = ?
grams H2O = moles H2O x molar mass H2O = ?
Post your work if you get stuck.