Answer: 81.10 g Na
Step-by-step explanation:
The problem indicates the equation is already balanced.
Start with what you are given (56.44 g O₂). Use the molar mass of O₂, the balanced equation to determine the ratio of moles of Na to moles of O₂, and then use the molar mass of Na to find the grams of Na created.
56.44 g O₂ x (1 mol O₂/32.00 g O₂) x (2 mol Na/1 mol O₂) x 23 g Na/1 mol Na) = 2596.24 g/32.00 = 81.13 g Na
Note that all units cancel except for grams of Na, which is what you want.