Final answer:
The mass of oxygen gas consumed is found by subtracting the initial mass of magnesium (0.53 grams) from the final mass of magnesium oxide (1.21 grams), which equals to 0.68 grams of oxygen gas.
Step-by-step explanation:
To determine the mass of oxygen gas consumed when a 0.53-gram piece of magnesium burns to form 1.21 grams of magnesium oxide, we apply the law of conservation of mass. This law states that no matter is lost or created in a chemical reaction. Therefore, to find the mass of oxygen, we can subtract the initial mass of magnesium from the mass of the magnesium oxide produced:
- Mass of magnesium oxide (MgO) = 1.21 grams
- Mass of magnesium (Mg) = 0.53 grams
- Mass of oxygen gas (O2) = Mass of MgO - Mass of Mg
- Mass of oxygen gas (O2) = 1.21 grams - 0.53 grams
- Mass of oxygen gas (O2) = 0.68 grams
This calculation aligns with the principle of mass conservation, demonstrating that the mass of magnesium and oxygen gas before the reaction equals the mass of magnesium oxide after the reaction.