Answer:
12.8 moles
Step-by-step explanation:
The formula for water is H2O, so for every mole of water, there are two moles of hydrogen and one mole of oxygen.
As the ratio of oxygen particles to water particles is one to one, 12.8 moles of oxygen are required to produce 12.8 moles of water.
Therefore, 12.8 moles of water are produced from 12.8 moles of oxygen (assuming hydrogen is available in excess).