Why Is Carbon Dioxide Mixed In Cold Drinks And Beverages?

One of the most important factors when it comes to mixing any gas with a liquid is solubility, and carbon dioxide is highly soluble in water. In fact, it's the most soluble of the common, non-toxic gases with high solubility. To give you an idea, around 1.5 liters of carbon dioxide can be dissolved in 1 liter of water at normal atmospheric pressure.

Compared to other common gases, such as helium and hydrogen, CO2 mixes much better with water. Other gases that do mix with water, like hydrogen sulfide, ammonia, and sulfur dioxide, are usually toxic. Although there are some drinks that use other gases, they tend to be more expensive and less commonly consumed by the general public.