Chemistry help on homework

Question

How many grams of oxygen gas react to give 2.00 g of ZnO?

2Zn(s)+O2(g)⟶Δ2ZnO(s)

Express your answer with the appropriate units.

Answer 1

2Zn(s)+O2(g)⟶ 2 ZnO(s)

2.00 g ZnO x 1 mole/81.4 g = 0.5535 moles ZnO

moles O₂ needed = 0.5535 mol ZnO x1 mol O₂/2 mol ZnO = 0.2768 moles O₂

Mass O₂ = 0.2768 moles x 32 g/mol = 8.86 g O₂ needed

This is assuming Zn is not limiting and is given to 3 sig figs.