Vitamin K antagonists (VKA) are a group of substances that reduce blood clotting by reducing the action of vitamin K. They are used as anticoagulant medications in the prevention of thrombosis, and in pest control, as rodenticides. 1  1 Mechanism of action.  2 Coumarins (4-hydroxycoumarins)
Calculate the average atomic mass of oxygen. Solution: ((15.994915*99.757) + (16.999132*0.038) + (17.999160*0.205))/100 = 15.999405 . Using our equation for determining average atomic mass, we see that the average atomic mass for oxygen is 15.999405 amu. If we check the periodic table, we will see that our average atomic mass is the same as the atomic mass indicated on the element oxygen. Ã
Dissolved oxygen is measured in milligrams per liter (mg/L). One milligram (mg) is 1/1000 (one thousandth) of a gram or 1/1000000 (one millionth) of a kilogram. 1 kilogram of water weighs 1 kilogram and occupies a volume of 1 liter (L).Therefore, expressing dissolved oxygen in mg/L is the same as using units of parts per million (ppm).Twelve parts per million (12 mg/L) is the highest amount of oxygen that can be dissolved in water under standard barometric pressures (sea level); 12 mg/L is known as the saturation point.Zero parts per million (0 mg/L) is the lowest amount of dissolved oxygen in water.ince, the amount of oxygen dissolved in water is small compared to the weight of water, it isn't appropriate to describe the level of dissolved oxygen in terms of a percentage.