Carbonic acid is a weak acid, so the acidity isn’t as strong. Most the protons are bound in carbonic acid. Whereas in dissolved hydrogen, all the hydrogen molecules are necessarily ionized, giving what should be an acid quite some orders stronger.
Chemistry teacher here. No way do those hydrogen molecules ionize. If they ionize, that would require making the entire solution positively charged, or filled with singlet hydrogen. Just like dissolving oxygen or nitrogen in water, the gas will dissolve, but not dissociate.
Carbonic acid is a weak acid, so the acidity isn’t as strong. Most the protons are bound in carbonic acid. Whereas in dissolved hydrogen, all the hydrogen molecules are necessarily ionized, giving what should be an acid quite some orders stronger.
Chemistry teacher here. No way do those hydrogen molecules ionize. If they ionize, that would require making the entire solution positively charged, or filled with singlet hydrogen. Just like dissolving oxygen or nitrogen in water, the gas will dissolve, but not dissociate.
(See my reply above for full details)