To determine the limiting reactant, we need to calculate the amount of moles of each reactant.
First, let's calculate the number of moles of P4O10:
Molar mass of P4O10 = 4(30.97) + 10(15.99) = 283.88 g/mol
Number of moles of P4O10 = 5.00 g / 283.88 g/mol = 0.01764 mol
Now, let's calculate the number of moles of water:
Molar mass of H2O = 2(1.01) + 15.99 = 18.02 g/mol
Number of moles of water = 1.50 g / 18.02 g/mol = 0.08324 mol
The mole ratio between P4O10 and H2O is 1:4 (from the balanced chemical equation).
So, if all the P4O10 reacted with water, we would need 4 times the moles of water to fully react.
Moles of H2O needed to react with all the P4O10 = 4 x 0.01764 mol = 0.07056 mol
Since the actual number of moles of water (0.08324 mol) is greater than the required number of moles of water (0.07056 mol), there is an excess of water. Therefore, the limiting reactant is P4O10.