P_(2)O_(3)+3H_(2)Oarrow 2H_(3)PO_(3) How many grams of diphosphorus trioxide, P_(2)O_(3) . are required to react completely with 4.0 moles H_(2)O ? molar mass P_(2)O_(3):109.94g/mol [?]gP_(2)O_(3)

1. Determine mole ratio from balanced equation From the equation, 1 mole of reacts with 3 moles of .2. Calculate moles of needed For 4.0 moles of , use the ratio: . Thus, moles of .3. Convert moles of to grams Use the formula: **mass = moles molar mass**. Mass of g/mol.