how many grams of oxygen are required to react completely with 5.56 moles of hydrogen to form water?

Question

2H2 + O2. 2H2O

Answer 1

2H2 + O2 ==> 2H2O
5.56 mols H2 will require 1/2 that or 5.56/2 = 2.78 mols O2.
grams O2 = mols O2 x molar mass O2 = ?

Answer 2

88.96g