Final answer:
In the given electrolysis reaction, 64.0 grams of water decomposes to form 7.2 grams of hydrogen gas. The mass of oxygen gas formed can be calculated by finding the difference between the initial mass of water and the mass of hydrogen gas formed, which is 56.8 grams.
Step-by-step explanation:
Water can be decomposed into hydrogen gas and oxygen gas through a process called electrolysis. The balanced equation for this reaction is 2 H₂O(1) → 2 H₂(g) + O₂(g).
According to the given information, 64.0 grams of water decomposes, resulting in the formation of 7.2 grams of hydrogen gas. To find the grams of oxygen gas formed, we need to calculate the difference in mass between the initial mass of water and the mass of hydrogen gas formed.
Initial mass of water = 64.0 grams
Mass of hydrogen gas formed = 7.2 grams
Mass of oxygen gas formed = Initial mass of water - Mass of hydrogen gas formed = 64.0 grams - 7.2 grams = 56.8 grams.