Why is carbon dioxide used in soda? What makes it preferable to other gases for this purpose?

  • 6
    $\begingroup$ Because it tastes better than chlorine or any other gas, I guess. $\endgroup$ Oct 26, 2015 at 7:11
  • $\begingroup$ Almost a $+1$ to your comment @IvanNeretin but I personally dislike drinks with extra gasses in them ;) $\endgroup$
    – Jan
    Oct 26, 2015 at 14:34

2 Answers 2


You are approaching this question from the wrong angle. One does not simply ‘add a gas to a drink’ for no reason. If one wanted to add any gas, one would probably use boring old nitrogen since it is the most abundant in the atmosphere (See the Guiness example as pointed out by Ivan in a comment).

Carbon dioxide is present in fizzy drinks such as soda to give them their fizz. The reason lies in the equilibrium between $\ce{CO2 + H2O}$, $\ce{H2CO3}$, $\ce{HCO3-}$ and $\ce{CO3^2-}$. No other gas would display this behaviour and give a slight acidic taste along with the tingle on the tongue.

Note that oxygen is sometimes added to drinks to improve the assumed value. It doesn’t really do anything but sells for a higher price. I don’t think that would be the case for nitrogen- or argon-enriched water (but I am likely underestimating the powers of marketing here). Many other gases would simply make no sense to add at all because they are either toxic ($\ce{Cl2, H2S}$) or disgusting ($\ce{H2S}$) or simply way too expensive ($\ce{Xe}$).

  • 2
    $\begingroup$ Nitrogen is a technical challenge, for it does not dissolve that well. However, they do exactly that with Guinness beer. $\endgroup$ Oct 26, 2015 at 14:50
  • $\begingroup$ Oxygen (or ozone that breaks down to give oxygen) could destroy yucky organisms or organics, although one can ask how long this effect actually lasts. $\endgroup$ Mar 10, 2018 at 17:24

Carbon dioxide gas is comparatively more stable and better dissolves in water rather than other common gases. Moreover, addition of the gas gives the drink the fizziness which in other ways react with water to form carbonic acid which in turn produces a lemonish flavour...Over all, carbon dioxide is prefered as it is more feasible...and for a variety of other reasons. Hope that helps!

  • 1
    $\begingroup$ Maybe you could expand upon what the 'other reasons' are? $\endgroup$
    – bon
    Oct 26, 2015 at 10:13
  • $\begingroup$ Certain gases can be toxic for human consumption, CO2 also gives the tingly feeling of the drink,... $\endgroup$ Oct 26, 2015 at 10:21

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