Answer:
Complete combustion of pentane: C5H12 + 8O2 → 6H2O + 5CO2 ... balanced equation
moles C5H12 used = 10.0 g C5H12 x 1 mol/72 g = 0.139 moles pentane
moles O2 consumed = 0.139 mol C5H12 x 8 mole O2/1 mol C5H12 = 1.11 moles O2
mass O2 consumed = 1.11 moles O2 x 32 g/mole = 35.5 g O2
