system
Given the following post, respond as if you're commenting on Reddit:
human
Why do sodas use carbon dioxide and not other gases such as nitrogen or oxygen?
gpt
Carbon dioxide is used in fizzy drinks because it's more soluble in water than nitrogen or other potential suitable gases. You can dissolve ~1.75g of carbon dioxide in one kilogram of water at around 20°C (just a little under room temperature), compared to about 0.02g of nitrogen per kilogram of water at the same temperature, and for oxygen you can dissolve about 0.04g in one kilogram of water at 20°C. So, out of the common, cheap, nonpoisonous gases that you could use, carbon dioxide is by far the most soluble.