why do carbonated drinks become "flat" after they've been opened and left uncapped?

Answer 1

Carbonated drinks are made by adding the carbonation to the liquid under high pressures. The ideal range is 4-6 atmospheres. At 3atm or lower, the beverage tastes "flat", while at 7+ atm is when you have more fizz and bubbles that leaves you with half a cup once it's all settled.

Sodas taste flat after they're opened because the pressure inside has been released. Since the high pressure keeping the carbonation in place is gone, it begins to escape out into the open system of the room.

Answer 2

Carbonated drinks have carbon dioxide dissolved in water to produce the fizz. The solubility of CO2 in water increases with higher pressure and lower temperature. When you pop open a can, you greatly reduce the pressure causing some foaming. The open can slowly warms over time, reducing solubility and causing more CO2 to come out of solution. Finally, all this takes a while because equilibrium is not immediately achieved but takes quite a while.

Answer 3

Drinks like Coke and Sprite contain carbon dioxide, that's where the fizz is from. Once the can is opened (or bottle, etc) the pressure of the can drops, and now the CO2 that was stored in the can eventually diffuses out of the drink into the air. So what's left is just the liquid coke, minus the cabon dioxide, or not it tastes "flat." Hope that helps.

Answer 4

Dissipation of the Carbonation.
It just like water will evaporate from a glass over time. Just the CO2 Evaporates faster. Hope this make sense.

Answer 5

the carbondioxide gas which is present in the carbonated drinks escapes from the drink if left open, so the drink becomes flat.

Answer 6

the higher temperatures causes the gas to be "undissolved" in the liquid. the gas is the carbonation. and since its left open, the CO2 just leaves into the air

Answer 7

The carbon dioxide escapes and evaporates.