Problem 5-81

CH3OH(ℓ) + O2(g) → CO2(g) + H2O(g)

First, balance the equation

Then, the number of mole of CH3OH is:

50.0 mL CH3OH × 0.850 g  = 42.5 g
mL
42.5 g × 1 mol  = 1.326 mol CH3OH
32.042 g

The number of mole of oxygen present in 22.8 L O2(g) at 27 °C and 2.00 atm is, using PV=nRT: n = 1.851 mol O2

Once the equation is balanced, it is quite easy to identify the limiting reactant.
Then, the number of mole of H2O produced, assuming a %yield = 100% can be calculated