# How much carbon dioxide do we actually ingest from a can of coke?

On this most trustworthy page it states that a 355 mL can of coke contains on average about 2.2 grams of carbon dioxide. As far as I know, this carbon dioxide can exist in solution as carbonic acid, and is what gives coke it's nice taste. However, when we open a can of coke, there is a hissing noise as carbon dioxide is released (presumably because the carbon dioxide was under a lot of pressure), and hence we never actually ingest 2.2 grams worth of carbon dioxide in the form of carbonic acid. Over time, the carbon dioxide continues to bubble out of solution. How would I get a rough estimate of the actual amount of carbon dioxide that I ingest in a 355 mL can of coke? (Just an order of magnitude, for instance ingesting 1% of the 2.2grams as opposed to 10% is a big difference). Also, how much would the temperature of the environment affect the amount of carbon dioxide lost?

Whatever $CO_2$ you ingest will ultimately be released from your drink in your stomach and will come out as burps. The solubility of $CO_2$ is $90cm^3$ per 100g of water at 1 bar pressure and room temperature. As temperature increases, this value decreases, which means that less amount of $CO_2$ stays in the water. For a 355ml can of cool drink (at room temperature), which we can assume as water, the amount of $CO_2$ present at normal atmospheric pressure comes out to be roughly 0.6g. This is the amount you ingest.(Roughly 25%). The rest is lost in two ways
You can look up the molar solubility values of $CO_2$ online.