Then take those 2 pounds and turn them into Kilograms by whatever "magic math" formula it takes to do so. ~2.2 pounds per Kilogram, so almost 1 full Kilogram, over a Kilogram if they gt a refill.
Also I had forgotten that soda uses CO2 to get the fizz in it. Even the water has traces of CO2 in it, carbonated water, because they use it to mix with the syrup to make soda. Sometimes if the machine isn't set up properly, there are traces of CO2 in the water they give. Litely carbonated water.