You've probably heard I didn't know I was pregnant stories that went something like this: A woman claims she took an at-home pregnancy test that came back negative, but, lo and behold, she really was pregnant -- and the pregnancy progressed without her knowledge.
Carbonation in anything you drink allows it to enter the bloodstream faster. There is no difference with an alcoholic beverage. If you drink alcohol that is either carbonated or mixed with a carbonated beverage, then it will absorb into the bloodstream faster than drinks that are not carbonated. Examples are cocktails such as Jack and Coke, which is whiskey mixed with Coca-Cola.
Though dehydration is a major factor, it's not the only one. Everyone has a unique physiological response to alcohol in terms of how it's broken down and eliminated by the body. And the way you metabolize alcohol can certainly have an effect on the onset, severity and duration of a hangover. Alcohol is metabolized in two stages: one group of enzymes break down ethanol -- the alcohol that you ingest -- into acetaldehyde.