Stoichiometry Help!!!?

Question

I really need to know how to do this question:

What number of moles of O2 is needed to produce 14.2 grams of P4O10 from P? (Molecular wight P4O10 = 284 g

Answer 1

The above answer is correct, but he lacks the detail you need to LEARN how to do these problems. Use the following steps, in order:

1) Write the correct chemical formulas for everything involved in the question.

2) Write an equation showing reactants and products.

3) Balance this equation.

4) Convert everything into moles.

5) Look at the ratio of moles involved in the equation. (In the above example, you need to know moles of 02 and moles P4010. And the ratio is 5:1. You get that from the balanced equation)

6) Detemine the number of moles needed for your unknown. (ie: the question, ex: what number of moles of 02 is needed.)

7) If necessary, convert that answer to grams or liters.

Answer 2

14.2 g P4O10 = 14.2/284 moles P4O10 = 0.05 moles P4O10
For preparing 1 mole P4O10 you need 5 mole O2.
So to prepare 0.05 mole P4O10 you need .05*5 mole O2 = 0.25 mole O2

Answer 3

0.25 mol