Answer:
Step-by-step explanation:
1. Write down the balanced equation
2. Use molar mass of O2 (32g/mol) divided by the given mass to derive the amount of mols
3. multiply the answer by 2/3 (divide by 3 then multiply by 2), to ensure the mols are in correct proportion
4. Use given molar mass and multiply it by the amount
5. Make sure to use proper significant digits (3 in this case) and units :)