For the reaction, calculate how many moles

Question

For the reaction, calculate how many moles of the product form when 2.57 mol of Na completely reacts.
Assume that there is more than enough of the other reactant.
2Na(s)+O2(g)→Na2O2(s)

Answer 1

2Na(s)+O₂(g)→Na₂O₂(s)  balanced equation

From this balanced equation you can tell that TWO moles Na(s) react with ONE mole O2 to make ONE mole Na₂O₂.

So, if you have 2.57 moles of Na(s), how many moles of of Na₂O₂ do you think you can make?

It's a simple proportion:  2 moles Na makes 1 moles Na₂O₂ just as 2.57 moles Na makes x moles O₂

2/1 = 2.57/x

x = 2.57/2 = moles Na₂O₂

Solve