Phosphorus burns in air to produce a phosphorus oxide in the following reaction:

Phosphorus burns in air to produce a phosphorus oxide in the following reaction:
4P(s)+5O2(g)⟶P4O10?(s)

a. What mass of phosphorus will be needed to produce 3.25 mol of P4O10?
b. If 0.489 mol of phosphorus burns, what mass of oxygen is used? What mass of P4O10? is produced?