The oxygen produced was collected over water. a sample of kclo3 produced 705 ml of oxygen saturated with water vapor at 20.0C where the vapor pressure of water is 17.54 mmhg. the total gas pressure was 1.104 atm. what is the mass of kclo3 decomposed? 2KClO3 (s) = 2KCl (s) + 3O2 (g)